FR3074597A1 - METHOD AND APPARATUS FOR CONSTRUCTING A REFERENCE BASE USED BY AN ELECTRONIC MESSAGING TOOL TO DETERMINE A PRIORITY LEVEL OF AN ELECTRONIC MESSAGE - Google Patents

Abstract

Method and apparatus for constructing a reference database used by an electronic mail tool to determine a priority level of an electronic message The construction method comprises: for each message of a plurality of previously received and processed electronic messages by a user: ○ an evaluation step (E20), for each action of a plurality of predetermined actions that may have been performed on the message, a score associated with this action from a set time by the user to perform the action on the message; A step (E40) for determining a signature of the message formed of a set of elements extracted from the message; for each determined signature corresponding to at least one of the plurality of electronic messages: an estimation step (E50), a significance level of the messages corresponding to the signature, comparing with at least one predetermined threshold; a global score determined for the signature and resulting from a weighted sum of scores evaluated for each message corresponding to the signature and associated with the plurality of actions; ○ a storage step (E60) in the reference base, in association with the signature, of the estimated importance level.

Description

Method and device for constructing a reference base used by an electronic messaging tool to determine a priority level of an electronic message

The construction process includes:

- for each message of a plurality of electronic messages previously received and processed by a user:

O an evaluation step (E20), for each action of a plurality of predetermined actions likely to have been carried out on the message, of a score associated with this action from a time set by the user to perform the action on the message;

O a step (E40) of determining a signature of the message formed of a set of elements extracted from the message;

- for each determined signature corresponding to at least one message from the plurality of electronic messages:

An estimation step (E50), of a level of importance of the messages corresponding to the signature, by comparing with at least a predetermined threshold, a so-called global score determined for the signature and resulting from a weighted sum of the scores evaluated for each message corresponding to the signature and associated with the plurality of actions; One step (E60) of storing, in the reference base, in association with the signature, the estimated level of importance.

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Invention background

The invention relates to the general field of telecommunications and relates more particularly to an electronic messaging tool.

It more specifically aims at a mechanism making it possible to automatically differentiate the electronic messages received by a user according to their importance for the user by assigning to these messages a level of priority. Given the increasing number of electronic messages received today by each user, such a mechanism is particularly useful. It allows in particular to automate the processing of electronic messages and to have differentiated processing according to the priority level associated with each message. This can prevent the user from being overwhelmed by unnecessary information while ensuring that no important information is missing.

In the current state of the art, various strategies are used by electronic messaging tools to associate a priority or importance level with electronic messages received by a user.

According to a first strategy, it is the user who is invited to identify himself the electronic messages which he has received and which he considers as important or priority. It can for this purpose use an indicator (i.e. a tag) provided by the messaging tool that it associates with messages considered to be important. This first strategy, however, requires user intervention.

According to a second strategy, it is the electronic messaging tool which indicates to the user, for example using a specific color code, electronic messages which seem important to him in view of a set of predefined criteria. . Such criteria are for example the fact that the electronic message was sent directly to the user, or because of its sender, or even because the user replied to or forwarded it, etc. These criteria are defined by the electronic messaging tool: the user can then, if he wishes, confirm this classification or cancel it. The criteria used by the electronic messaging tool to try to prioritize electronic messages are general enough to apply to all users. It is therefore understandable that they are not necessarily relevant and suitable for a given user and lead to identifying as important electronic messages which are not for the user.

There is therefore a need for a mechanism enabling a priority or importance level relevant to this user to be associated with an electronic message received by a user.

Subject and summary of the invention

The invention responds in particular to this need by proposing a method of constructing a reference base, intended to be used by an electronic messaging tool to determine a priority level of an electronic message addressed to a user, said method of construction including:

- for each electronic message of a first plurality of electronic messages previously received and processed by the user:

o a step of evaluation, for each action of a plurality of predetermined actions likely to have been carried out on the electronic message, of a score associated with this action from a time taken by the user to perform said action on said electronic message;

a step of determining a signature of the electronic message formed of a predetermined set of elements extracted from the electronic message;

- for each determined signature corresponding to at least one electronic message from said first plurality of electronic messages:

a step of estimating a level of importance of the messages corresponding to said signature, by comparing with at least a predetermined threshold, a so-called global score determined for said signature and resulting from a weighted sum of the scores evaluated for each message corresponding to said signature and associated with said plurality of actions;

o a step of storing, in the reference base, in association with said signature, the estimated level of importance.

Correlatively, the invention relates to a construction device, configured to build a reference base intended to be used by an electronic messaging tool to determine a priority level of an electronic message addressed to a user, said device comprising:

Modules activated for each electronic message of a first plurality of electronic messages previously received and processed by the user, said modules comprising:

o an evaluation module, configured to evaluate for each action of a plurality of predetermined actions performed on the electronic message, a score associated with this action from a time taken by the user to perform said action on said e-mail ;

a module for determining a signature of the electronic message, configured to extract a predetermined set of elements from the electronic message and form said signature of the electronic message from the elements extracted;

Modules activated for each determined signature corresponding to at least one electronic message from said first plurality of electronic messages, said modules comprising:

a module for estimating a level of importance of the messages corresponding to said signature, configured to estimate said level of importance by comparing with at least a predetermined threshold, a so-called global score determined for said signature and resulting from a weighted sum of the scores evaluated for each message corresponding to said signature and associated with said plurality of actions;

o a storage module, configured to store in the reference base, in association with said signature, the estimated level of importance.

The invention therefore proposes the construction of a reference base intended to be used typically by the electronic messaging of a user to classify the electronic messages of this user, this reference base being constructed by carrying out an automatic learning of the processing habits. of the user with regard to his electronic messages. To carry out this learning, a sample of messages addressed to the user is preferably considered to be large enough to be significant of the habits of the user, for example a sample comprising at least 250 electronic messages.

More specifically, the invention proposes to extract, for each of the messages previously processed by the user and considered for the construction of the reference base, a signature representative of the content of this electronic message (in the broad sense of the term, it that is to say including the envelope or the signaling of the message and / or the body of the message itself), and to relate this signature to a level of importance determined taking into account the time taken by the user to perform various processing (actions within the meaning of the invention) on the electronic message.

The weighted combination of the scores associated with the different actions considered to assess the level of importance of the signature can be an average of the time taken by the user to perform these actions on the message, and where appropriate a score already associated with the signature in the reference base. This makes it possible to take into account equally different actions carried out by the user on the message and which are significant in determining whether or not a user gives importance to a message, otherwise whether or not he considers it a priority.

The treatments or actions taken into account to determine the level of importance of an electronic message for the user can typically include at least:

- an opening of the electronic message;

- a reading of the electronic message (that is to say a focus itself on this message or a display of the message in the foreground); and - a response to the electronic message.

The inventors have indeed found (via tests) that the times taken by the user to execute these three types of actions on an electronic message are particularly relevant for evaluating the importance of a message for a user. Of course, this list is not exhaustive and other actions can be taken into account to assess a level of importance of an electronic message, such as for example the deletion of the electronic message, the transfer of this electronic message to a other user, etc. It is also possible to take into account the specificities of such actions such as for example the fact that an electronic message is immediately deleted, the passage of the message from an unread status to a read status, etc.

As a variant, one can choose to assign different weights to the different actions considered depending on whether they are more or less relevant for evaluating the level of importance of the user's electronic messages. The weights applied may depend on the user in question in order to take even more account of the processing habits of this user. Such weights can be easily determined by learning.

In a particular embodiment, during the storage step, the overall score determined for the signature is stored in the reference base in association with the signature and the level of importance estimated for this signature.

This embodiment allows an update of the reference base, as detailed later.

The predetermined set of elements considered to form the signature of each electronic message can include various elements representative of the electronic message and making it possible to characterize its content.

In a particular embodiment, said predetermined set of elements from which the signature of the electronic message is formed comprises at least:

- a sender of the electronic message; and / or - at least one keyword extracted from an object and / or from a body of the electronic message.

It can alternatively include any other type of metadata attached to the electronic message, that is to say contained in the envelope (or signaling) of this message or in its body. Such a signature can be easily extracted from an electronic message and includes elements making it possible to identify the main themes of this message.

The invention therefore offers a means of prioritizing electronic messages addressed to a user which takes account not only of the content of electronic messages but also of the processing that the user usually applies to these electronic messages, in other words the use that he usually does. This makes it possible to have a classification of electronic messages intended for a user adapted to this user (i.e. personalized), and not solely based on general criteria which may not be relevant for this user. The invention thus makes it possible to improve the strategies envisaged in the prior art by offering a personalized classification of the user's electronic messages.

In a particular embodiment, the score associated with a predetermined action is evaluated by comparing the time taken by the user to perform this action on the electronic message with respect to an average value of this time calculated on a second plurality of electronic messages. previously received and processed by the user.

The second plurality of electronic messages may or may not be identical to the first plurality of electronic messages.

Such a comparison, which is based on statistics processing the user's messages, makes it possible to determine whether the time spent by the user to perform said action on the electronic message differs more or less strongly from the average time spent by the user. user to perform this action on other messages: this makes it possible to identify an electronic message for which the user has had a treatment that differs from the average. The inventors in fact start from the postulate that according to the action considered (for example opening, reading / focus and response to the electronic message), and according to whether the duration observed to execute this action on the message is more or less long than the average time used to execute this same action on other messages, it is possible to deduce whether the message in question is important or not for the user. So, for example, we can assume that if the user opened a message faster than he opened his electronic messages on average, it means that this message is of particular importance to him. The same is true if the user responded to it faster on average than he usually does to his messages. Conversely, it can be assumed that if the user opens an electronic message too quickly compared to the average time usually taken, it is that this message is not important. The choice of one or the other of the hypotheses is configurable, for example by the user, or after tests carried out on a plurality of users or the user in question.

In a particular embodiment of the invention, the level of importance has a discrete value chosen from a predetermined number of values. For example, the level of importance can be selected from at least two values comprising a first value representative of a signature of an important electronic message (eg “important”, “priority” or “1”) and a second value representative of a signature of a secondary electronic message (eg "secondary", "not priority" or "0").

One can, as a variant, envisage that the level of importance could also take a third value representative of a signature of an unclassified electronic message, that is to say for which it was not possible to estimate with sufficient reliability or precision the level of importance that the user assigns to messages corresponding to this signature.

In yet another variant, the signatures of messages which could not be classified are not associated in the reference base with any level of importance (that is to say that the level of importance which is associated with them is empty).

It is of course possible to consider more values than two or three values to qualify the level of importance of a message signature for a user.

The reference base constructed thanks to the invention advantageously makes it possible to easily classify the electronic messages received by a user according to their priority.

Thus, according to another aspect, the invention relates to a method for determining a priority level of an electronic message addressed to a user, this method comprising:

A step of obtaining a reference base constructed using a construction method according to the invention from a first plurality of electronic messages previously received and processed by the user via an electronic messaging tool;

- following the reception by the electronic messaging tool of a new electronic message addressed to the user:

a step of determining a signature of the new electronic message, said signature being formed of elements extracted from the new electronic message and corresponding to said predetermined set of elements (ie to the predetermined set of elements taken into account to determine the reference base signatures);

o a step of comparing the signature of the new electronic message with the signatures stored in the reference database; and a step of determining a priority level of the new electronic message from at least one level of importance associated in the reference base with at least one signature having a similarity with the signature of the new electronic message.

Correlatively, the invention relates to a device for determining a priority level of an electronic message addressed to a user, said device comprising:

- an access module, configured to access a reference base constructed by a construction device according to the invention from a first plurality of electronic messages previously received and processed by the user via an electronic messaging tool;

- a reception module, configured to detect the reception by the electronic messaging tool of new electronic messages addressed to the user;

A plurality of modules, activated following the detection by the reception module of the reception of a said new electronic message addressed to the user, said plurality of modules comprising:

a first determination module, configured to determine a signature of the new electronic message, said signature being formed of elements extracted from the new electronic message and corresponding to said predetermined set of elements;

o a comparison module, configured to compare the signature of the new electronic message with the signatures stored in the reference database; and a second determination module, configured to determine a priority level of the new electronic message from at least one level of importance associated in the reference base with at least one signature having a similarity with the signature of the new message electronic.

The invention also relates to an electronic messaging tool comprising a determination device according to the invention.

In a particular embodiment, the electronic messaging tool further comprises a construction device according to the invention.

The aforementioned method, determination device and messaging tool use the reference base constructed in accordance with the invention to classify incoming electronic messages from the user according to their priority. They therefore benefit from the same advantages mentioned above as the method and the device for constructing the reference base.

In a particular embodiment, the determination method further comprises a step of processing the new electronic message, this processing being selected as a function of the priority level determined for this new electronic message.

Thanks to the invention, it is possible for an electronic messaging tool integrating the invention to propose differentiated processing to the user of the electronic messages that he receives as a function of the priority level determined for these electronic messages. No limitation is attached to the nature of the processing that can be applied: it can occur at the level of the display of electronic messages (for example, messages identified as having a higher priority level can be displayed first. , and / or messages identified as having a lower priority level can be hidden, in order not to overwhelm the user with too much information), at the level of notification of incoming electronic messages (for example, only messages identified as priority are notified to the user, or a reminder can be made to the user when a message identified as priority has not been processed after a certain time, etc.), in terms of classification or archiving in various directories operated by the messaging tool for electronic messages received, etc.

In a particular embodiment, the step of determining the priority level of the new electronic message comprises:

- searching the reference database for at least one signature having at least one element common to the signature of the new electronic message;

- the determination, for each signature identified in the reference base during the search, of a degree of similarity with the signature of the new electronic message;

the priority level of the new electronic message being determined from the level of importance associated with the signature identified in the reference base having the highest degree of similarity with the signature of the new electronic message.

This embodiment takes into account the fact that an electronic message received does not necessarily correspond to a single signature indexed in the reference base. By selecting the signature corresponding to the highest degree of similarity, the invention provides a simple mechanism which makes it possible to ensure the reliability of the priority level determined for the message.

In a particular embodiment, the determination method further comprises:

A step of evaluation, for at least one action of said plurality of predetermined actions (ie for the same actions as those considered during the construction of the reference base), of a score associated with this action from '' a time taken by the user to perform this action on the new electronic message; and a step of updating a so-called temporary score associated with the signature of the new electronic message with a weighted sum of the temporary score and the scores evaluated for said new message and associated with said at least one action; and - upon detection of a predetermined event, a step of updating the reference base comprising:

o the evaluation of an overall score associated with the signature of the new message from the temporary score associated with this signature, and if the signature is already present in the reference base, of the global score associated in the reference base with the signature;

o estimating the level of importance of the messages corresponding to the signature of the new message by comparing the overall score evaluated with said at least one predetermined threshold; and o updating the reference level of the level of importance and the overall score associated with the signature.

The event triggering the update can be of different types. The update can be done for example at (pre) determined times (for example at the start of the messaging tool) or periodically (for example, every day at a given time of the day) or when we detect a change in user habits, etc. The triggering event (or events) can advantageously be configured.

This embodiment makes it possible to dynamically feed the reference base not only with new signatures, but also to take into account the evolution over time of the user's processing habits with regard to his electronic messages via the update of existing signatures. Such an evolution can be linked for example to a change of context of the user. In a professional sphere, such a change of context may arise in particular from a change in the user's collaborators, project, etc., such changes being likely to be reflected in the content of electronic messages received by the user, and in particular on the senders of these messages or on the words used in these messages, and to have an impact on the importance perceived by the user of the new messages received. Thus, thanks to this embodiment, if the habits of the user evolve over time, this will gradually be reflected in the reference base by an evolution in the level of importance associated with certain message signatures.

A dynamic and continuous learning of the processing habits of the user with regard to his electronic messages is therefore carried out in this embodiment, allowing a reliable and precise classification of his electronic messages.

This embodiment also makes it possible to make the learning carried out on the habits of the user more reliable, in particular on the signatures already existing in the database.

Updating the database on detection of specific events also makes it possible to have a compromise between complexity and relevance of the reference database to prioritize user messages.

In a particular embodiment, the different steps of the construction method and / or of the determination method are determined by instructions from computer programs.

Consequently, the invention also relates to a computer program on an information medium, this program being capable of being implemented in a construction device, a determination device or more generally in a computer, this program comprising instructions adapted to the implementation of the steps of a construction or determination process as described above.

This program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

The invention also relates to an information or recording medium readable by a computer, and comprising instructions of a computer program as mentioned above.

The information or recording medium can be any entity or device capable of storing the program. For example, the support may include a storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or else a magnetic recording means, for example a floppy disk or a disc. hard.

On the other hand, the information or recording medium can be a transmissible medium such as an electrical or optical signal, which can be routed via an electrical or optical cable, by radio or by other means. The program according to the invention can in particular be downloaded from a network of the Internet type.

Alternatively, the information or recording medium can be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the process in question.

It is also conceivable, in other embodiments, that the construction method, the determination method, the construction device, the determination device and the electronic messaging tool according to the invention have all or part in combination of the above characteristics.

Brief description of the drawings

Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an embodiment thereof devoid of any limiting character. In the figures:

- Figure 1 shows a computer system on which is installed an electronic messaging tool according to the invention, in a particular embodiment;

- Figure 2 shows schematically the hardware architecture of the computer system of Figure 1;

- Figure 3 shows, in the form of a flowchart, the main steps of a method of constructing a reference base in accordance with the invention, in a particular embodiment;

- Figure 4 illustrates an example of a reference base constructed using the method shown in Figure 3; and FIG. 5 represents, in the form of a flowchart, the main steps of a method for determining a priority level of an electronic message using a reference base constructed by means of the method represented in FIG. 3, in a particular embodiment.

Detailed description of the invention

FIG. 1 represents a computer system 1 such as a computer of a user U, comprising an electronic messaging tool 2 in accordance with the invention in a particular embodiment.

The electronic messaging tool 2 is software installed here on the computer 1 of the user U, and which allows the user U to receive and send electronic messages via a telecommunications network NW. No limitation is attached to the nature of the NW network. It can be a wired or wireless telecommunications network, mobile or fixed, etc.

As a variant, the electronic messaging tool 2 can be a web application installed on a remote server to which the user U accesses via his computer 1 and via the telecommunication network NW for example to send and receive electronic messages.

The messaging tool 2 installed on the computer 1 of the user U differs from the electronic messaging software known from the prior art in that it incorporates a device 3 for determination according to the invention, configured to determine priority levels for each of the electronic messages received by the user U via the electronic messaging tool 2. Such a priority level associated with an electronic message reflects the importance that the user U attaches to the electronic message. It makes it possible to classify the electronic messages of the user U according to their relevance for this one, that is to say their priority or their importance, and possibly to apply differentiated treatments between these messages in according to their priority level.

In order to determine the priority levels of electronic messages received by the user via the electronic messaging tool 2, the determination device 3 is based on a reference base 4, constructed by a construction device 5 in accordance with the invention, also integrated here into the electronic messaging tool 2. As a variant, the device 5 for constructing the reference base 4, the reference base 4 and / or the determination device 3 can be integrated into software other than the messaging tool 2.

By base is meant here any table or data structure making it possible to store data in structured form. According to the invention, the reference base 4 records, for several types of electronic messages previously received and processed by the user U, levels of importance estimated for the user U by automatic learning. This estimate takes into account the way in which the user U has processed these messages and more particularly the speed of execution of certain actions on these messages as described in more detail later.

The computer 1 of the user U has the hardware architecture illustrated in FIG. 2. It comprises in particular a processor 6, a random access memory 7, a read-only memory 8, a non-volatile flash memory 9 (in which is stored for example the reference base 4), as well as communication means 10 comprising one or more communication interfaces.

The communication means 10 allow the computer 1, via the electronic messaging tool 2, to send electronic messages on the NW network of which the user U is at the origin, and to receive via the NW network e-mail messages intended for this user.

The read-only memory 8 of the computer 1 constitutes a recording medium in accordance with the invention, readable by the processor 6 and on which computer programs PROG3 and PROG5 in accordance with the invention are recorded: the program PROG3 comprises instructions for the execution of the steps of the determination method according to the invention, which is implemented here by the determination device 3, while the program PROG5 includes instructions for the execution of the steps of the construction method according to the invention as implemented by the construction device 5.

More particularly, the computer program PROG5 defines functional modules and therefore software here of the construction device 5 integrated in the electronic messaging tool 2, and which is suitable for constructing the reference base 4 from a sample E of electronic messages previously received by the user via the electronic messaging tool 2 and already processed by the latter. This sample of messages can be stored by the messaging tool 2 locally on the computer 1, for example in its non-volatile memory 9, to facilitate access to these messages by the construction device 5 during the construction of the reference base 4, and / or in whole or in part on a remote server, accessible by the construction device 5 via the communication means 10 of the computer 1 and via the network NW.

By processing an electronic message, it is meant here that the user U has operated on his own initiative at least one action on this electronic message (such an action is distinguished from a programmed automatic processing carried out on the message such as for example l application of user-specified processing or filtering rules). No limitation is attached to the type (s) of actions that can be performed on this message. However, we are more particularly interested here in three types of actions, namely opening the electronic message, reading the electronic message (i.e. focusing on this message) and replying to this message. electronic.

The functional modules defined by the PROG5 program are based on and / or control the hardware elements 6-10 of the computer 1 mentioned above, and include in particular, as illustrated in FIG. 1:

- modules activated here for each electronic message in sample E, including:

o an evaluation module 5A, configured to evaluate for each action a plurality of predetermined actions performed on the electronic message (namely here the opening, reading and response to the electronic message), a score associated with this action from a time taken by the user to perform this action on the electronic message in question;

a module 5B for determining a signature of the electronic message, configured to extract a predetermined set of elements from the electronic message and form the signature of the electronic message from the elements extracted;

Modules activated for each signature determined by the determination module 5B and corresponding to at least one electronic message of the sample E comprising:

o an estimation module 5C of a level of importance of the messages corresponding to this signature, configured to estimate the level of importance by comparing with at least a predetermined threshold, a so-called global score determined for the signature and resulting from a weighted sum of the scores evaluated for each message of the sample E corresponding to this signature and associated with said plurality of actions;

o a storage module 5D, configured to store in the reference base 4, in association with the signature, the level of importance estimated by the estimation module 5C and, in the embodiment described here, the overall score determined for signing.

The functions of these modules are described in more detail later, with reference to the stages of the construction method according to the invention.

Similarly, the computer program PROG3 defines functional modules and therefore software here of the determination device 3 integrated in the messaging tool 2, and which is adapted, from the reference base 4 constructed by the device 5 of construction, to classify the incoming electronic messages intended for the user U, that is to say here to assign them a level of priority in accordance with the invention. The functional modules defined by the PROG3 program are based on and / or control the hardware elements 6-10 of the computer 1 mentioned above, and include in particular here, as illustrated in FIG. 1:

- an access module 3A, configured to access the reference base 4 constructed by the construction device 5;

A reception module 3B, configured to detect the reception by the electronic messaging tool 2 of new electronic messages addressed to the user U;

A plurality of modules, activated following the detection by the module 3B of reception of the reception of a new electronic message addressed to the user U, this plurality of modules comprising:

o a first determination module 3C, configured to determine a signature of the new electronic message, this signature being formed of elements extracted from the new electronic message and corresponding to the predetermined set of elements considered to form the signatures reported in the base 4 reference ;

o a 3D comparison module, configured to compare the signature of the new electronic message with the signatures stored in the reference base 4; and a second determination module 3E, configured to determine a priority level of the new electronic message from at least one level of importance associated in the base 4 with reference to at least one signature having a similarity with the signature of the new email message.

The PROG3 program also defines, in the embodiment described here, a module 3F for updating the reference base 4.

The functions of these modules are described in more detail later, with reference to the steps of the determination method according to the invention.

We will now describe in more detail the data recorded in the reference base 4 as well as the manner in which this reference base 4 is constructed by the construction device 5 in accordance with the invention.

FIG. 3 represents, in the form of a flowchart, the main steps of the construction method according to the invention as they are implemented by the construction device 5, in a particular embodiment, to build the base 4 of reference.

As mentioned previously, the construction device 5 uses, to construct the reference base 4, a sample E (first plurality of messages within the meaning of the invention) of electronic messages previously received by the user U and processed by the latter via email tool 2. In the embodiment described here, we consider by way of illustration a sample E comprising at least 250 electronic messages on which the user U has notably carried out the following three actions: opening and reading (focus on) of the message and response to the message.

It is assumed that the construction device 5 has, for each of the electronic messages of the sample E, the times taken by the user U to execute the three aforementioned actions (an action being considered as carried out upon its completion), in other words:

- the opening time of the message (referenced by To (M) below, M denoting the message considered), characterized by the time elapsed between the instant of receipt of the message by the user U on his messaging tool 2 electronic and the instant of opening of the message by the user U;

- the reading (or focus) time of the message (referenced by Tf (M) below), characterized by the time elapsed between the time when the message is opened by the user U and the time when it is closed, loss of focus, or sending of a response to this message, in other words by the duration over which the user U remained focused on the electronic message. In other words, the reading time Tf (M) of the message characterizes the duration during which the message is displayed in the foreground on the screen and is therefore likely to be read by the user; and - the response time to the message (referenced by Tr (M) below), characterized by the time elapsed between the instant of reception of the message by the user U on his electronic messaging tool 2 and the instant d send a response to this message.

Such execution times can be easily obtained or even estimated by the construction device 5 from information conventionally recorded by an electronic messaging tool such as tool 2 (instant of receipt of the message, instant of sending of a response, instant opening of the message). The way in which the electronic messaging tool 2 obtains such information is known per se and is not described in more detail here.

Note that to estimate these execution times, the construction device 5 can, depending on the context, take into account only certain time slots relevant in this context and / or only certain days of the week or even of the year. . Thus, for example, in a professional context, the construction device 5 can be configured to evaluate these execution times taking into account only the time range 8 am to 6 pm (or a time range predefined by default or by the user), excluding days of the weekend and / or vacation of user U (in other words, the time elapsed outside the time range 8 am to 6 pm and the weekend or vacation days of the user is not counted in the execution time of the action considered estimated by the construction system 5).

Likewise, the construction device 5 may not count in the execution times that it estimates the duration during which the user U is considered to be absent or not using his computer 1. Such a state of the user U can be easily detected by computer 1 and recorded for each electronic message in the sample E by detecting a lockout of user session U on his computer 1 or an unavailable state reported by a presence application installed on the computer. computer 1.

The construction device 5 then estimates the following statistics from the execution times available for each of the electronic messages of the sample E (second plurality of messages within the meaning of the invention, coinciding here with the first plurality of messages) ( step E10):

- the average opening time To_m of the messages in sample E, and the standard deviation σο observed on the opening times of the messages in sample E;

- the mean time Tf_m of reading (or focus) of the messages from sample E, and the standard deviation of observed over the reading times of the messages of sample E; and - the average response time Tr_m of the messages in sample E, and the standard deviation ar found in the response times of the messages in sample E.

Then, from these statistics, the construction device 5 evaluates, via its evaluation module 5A, for each electronic message M of the sample E and for each action of opening, reading and response considered, a score associated with this action for the message M (step E20).

More precisely, in the example envisaged here, it evaluates for each electronic message M:

- a score so (M) of importance associated with the action of opening the message M;

- an important score sf (M) associated with the action of reading the message M; and - an important score sr (M) associated with the response action to the message M.

In the embodiment described here, the evaluation module 5A evaluates each importance score associated with an action for each of the messages M by comparing the time taken by the user U to perform this corresponding action on the message M with respect to at the corresponding mean time and standard deviation evaluated during step E10.

More specifically, to evaluate the score so (M) associated with the message M, the evaluation module 5A compares the time To (M) of opening of the message M with the average opening time To_m and the standard deviation σο , and depending on the result of the comparison, assigns a value to the importance score so (M) associated with the message M. In the example envisaged here, the importance score so (M) is assigned by module 5A in applying the following rules:

- if To (M) <To_m-3ao: so (M) = 100;

- siTo (M) <To_m-1.5oo: so (M) = 75;

- if To (M) <To_m-ao: so (M) = 50;

- if To (M) <To_m-0.5ao: so (M) = 25;

- if To (M)> To_m-0.5oo: so (M) = 0.

Similarly, to evaluate the score sf (M) associated with the message M, the evaluation module 5A compares the time Tf (M) of reading the message M with the average reading time Tf_m and the standard deviation of, and according to the result of the comparison, assigns a value to the importance score sf (M) associated with the message M. In the example envisaged here, the importance score sf (M) is assigned by the module 5A by applying the following rules:

- if Tf (M)> Tf_m + 3of: sf (M) = 100;

- if Tf (M)> Tf_m + 1.5of: sf (M) = 75;

- if Tf (M)> Tf_m + crf: sf (M) = 50;

- if Tf (M)> Tf_m + 0.5af: sf (M) = 25;

- if Tf (M) <Tf_m + 0.5of: sf (M) = 0.

Finally, to evaluate the score sr (M) associated with the message M, the evaluation module 5A compares the response time Tr (M) to the message M with the average response time Tr_m and the standard deviation or, and as a function of the result of the comparison, assigns a value to the importance score sr (M) associated with the message M. In the example envisaged here, the importance score sr (M) is assigned by the module 5A by applying the following rules:

- if Tr (M) <Tr_m-3or: sr (M) = 100;

- if Tr (M) <Tr_m-1.5or: sr (M) = 75;

- if Tr (M) <Tr_m-or: sr (M) = 50;

- if Tr (M) <Tr_m-0.5or: sr (M) = 25;

- if Tr (M)> Tr_m-0.5or: sr (M) = 0.

Of course, the rules presented above, as well as the values of the scores assigned to the message M, are only given by way of illustration and other rules and / or score values can be used by the module 5A.

Then, the evaluation module 5A evaluates for each electronic message M of the sample E, an overall score of importance for the user U of the message M (step E30). This overall importance score noted s (M) is obtained by calculating a weighted sum of the scores so (M), sf (M) and sr (M) previously evaluated for the message M. In the embodiment described here, the weighted sum calculated by module 5A is an average of the scores so (M), sf (M) and sr (M).

It is noted that in the embodiment described here, for the sake of simplification, it is considered that the times To (M), Tf (M) and Tr (M) are available for each electronic message of the sample E, so that each of the scores so (M), sf (M) and sr (M) can be calculated. Alternatively, if there is no information concerning one or the other of the above times (for example because the action was not carried out by the user on the message considered), in this in this case the score corresponding to the action is not evaluated and is not taken into account in the calculation of the overall score.

Alternatively, module 5A can assign different weights to the different scores so (M), sf (M) and sr (M) to calculate the overall score s (M). The weights applied can be predefined and depend on the user U in order to take even more account of the processing habits of this user. Such weights can be easily determined by learning.

Then, for each message M of the sample E, the construction device 5, via its determination module 5B, determines a signature of the message M representative of this message M and referenced below by SIGN (M) (step E40) . This signature is formed from a predetermined set of elements extracted from the message M by the determination module 5B.

In the example envisaged here, the predetermined set of elements considered to determine the signature SIGN (M) of a message M comprises:

- an emitter E (M) of the electronic message M; and - a plurality of KEYW (M) keywords extracted from the electronic message and in particular from the subject as well as from the body of the electronic message M. The extracted keywords are preferably representative of the semantic content of the message, for example of the subject of the message body. These can be words strictly speaking contained in the message M or keywords derived from the words contained in the message M.

As a variant, the signature of the message M can be determined from other elements extracted from the electronic message M (from the envelope or the signaling of the message M, and / or from the semantic content of this message contained in the subject or in the body of the message).

In the embodiment described here, the module 5B determines the sender E (M) of the electronic message M by referring to a specific field (eg “From” or “From” field) of the electronic message M recording this sender. Such a field is known per se and is not detailed further here. The transmitter E (M) can be identified either by name or by electronic mail address.

To extract KEYW (M) keywords representative of the message M, the module 5B uses in the embodiment described here a semantic analysis tool. Such a tool is for example the TiLT tool described in particular in the document by J. Heinecke et al. entitled “TiLT: platform for the automatic processing of natural languages”, TAL. Flight. 49, n ° 2/2008, pages 17 to 41, available at the URL https://atala.org/IMG/pdf/TAL-2008-49-2-01-Heinecke.pdf.

This tool is configured here to extract at most two keywords from the subject of the electronic message M and five keywords from the body of the electronic message M. Of course, a different number of keywords can be extracted from the electronic message M.

Then the evaluation module 5A allocates to each distinct signature identified for the messages M of the sample E, an overall score of importance (step E50).

To this end, in the embodiment described here, if the module 5B detects that two electronic messages M and M '(or more) of the sample E have the same signature, the evaluation module 5A calculates the average of the scores s (M) and s (M ') associated with these two messages (or more) and associates with the common signature SIGN (M) = SIGN (M') the overall (average) score of importance noted s (SIGN ( M)) thus calculated.

If a single message M corresponds to the signature SIGN (M), the overall score of importance associated with the signature SIGN (M) is the overall score s (M) calculated for this message during step E30 (ie s ( SIGN (M)) = s (M)).

From the global scores s (SIGN (M)) estimated for each message signature distinct from the sample E, the estimation module 5C estimates a level of importance noted PL (SIGN (M)) of the messages corresponding to this signature (step E50).

In the example envisaged here, the importance level PL (SIGN (M)) is chosen by the estimation module 5C from two possible values: a first value denoted IMP (which can in particular be a character or a character string alphanumeric) representative of a signature of an important electronic message (for example 1, or “important” or “priority”), and a second value noted ΝΟΝ-IMP representative of a signature of a secondary electronic message (for example 0, or "not important" or "secondary").

In the embodiment described here, the assignment by module 5C of one or other of the values IMP and NON-IMP to a message M depends on whether the associated global importance score s (SIGN (M)) at the signature SIGN (M) is greater than or less than a predetermined THR-IMP threshold, in other words:

- if s (SIGN (M))> THR-IMP: PL (SIGN (M)) = IMP;

- otherwise: PL (SIGN (M)) = NON-IMP.

In the example envisaged here, THR-IMP is fixed at 50, the global scores being able to take values from 0 to 100.

Then, in accordance with the invention, the storage module 5D of the construction device 5 stores in the reference base 4, each signature SIGN (M) in association with the level of importance PL (SIGN (M)) estimated by the module 5C and the overall score s (SIGN (M)) determined for this signature by the module 5A (step E60).

FIG. 4 illustrates an example of a reference base 4 as constructed by the construction device 5. This base is in the form of a table comprising a plurality of rows corresponding to different message signatures and three columns, a first column SIGN to record the signatures of the messages, a second column to record the levels of importance PL associated with each signature, a third column to record the overall scores associated with each signature. The importance levels PL take two values, the value 1 designating an important level and the value 0 designating a secondary level.

Each signature is formed here of a character string representing an identifier of the sender of a message (eg Ul, U2, U3 or U4 in the base 4 illustrated in FIG. 4), and of a plurality of strings of characters representing the keywords extracted from each message. The keywords referenced by Wxx (with xx = l, 2, 3, 4 or 5 in the example illustrated in FIG. 4) designate the keywords extracted from the subject of the messages while the keywords referenced by Txx (with xx = 1,2,3 or 4 in the example illustrated in FIG. 4) designate the keywords extracted from the body of the messages by the semantic analysis tool used by the construction device 5.

The reference base 4 thus constructed by learning the habits of processing electronic messages of the user U is stored in the non-volatile memory 9 of the computer 1.

FIG. 5 represents the main steps of the method implemented by the determination device 3 for determining a priority level for each electronic message newly received by the messaging tool 2 and intended for the user U, in a particular mode of realization of the invention.

It is assumed here that the reference base 4 previously constructed by the construction device 5 and stored in the non-volatile memory 9 of the computer 1 is accessible, for example via a digital bus, by the access module 3A of the device 3 determining the electronic messaging tool 2 to allocate to each new electronic message received by the messaging tool 2 and intended for the user U, a priority level according to the invention. The construction of the reference base 4 and the provision of the device 3 for determining this base constitute a step for obtaining a reference base within the meaning of the invention (step F10).

It is now assumed that a new message Mnew addressed to the user U is received by the electronic messaging tool 2 (step F20).

Following the detection of the reception of the new Mnew message by the module 3B for receiving the determination device 3, the modules 3C to 3E of the determination device 3 are activated to determine a priority level for the Mnew message.

More particularly here, the first determination module 3C determines from the message Mnew a signature SIGN (Mnew) of this message (step F30). The signature SIGN (Mnew) is determined from the same set of elements extracted from the Mnew message as the signatures recorded in the reference base 4. It therefore includes here:

- an emitter E (Mnew) of the electronic message Mnew; and - a plurality of KEYW (Mnew) keywords extracted from the Mnew electronic message.

The first module 3C proceeds to determine the signature SIGN (Mnew) in the same way as the module 5B for determining the construction device 5 in particular preferably using the same semantic analysis tool (TiLT for example).

By way of illustration, using the notations of FIG. 4, it is assumed here that the signature SIGN (Mnew) determined for the message Mnew is formed of the elements U2, W5 and T4, ie SIGN (Mnew) = (U2, W5, T4 ). The signature SIGN (Mnew) is temporarily stored by the first module 3C in the non-volatile memory of the computer 1, in association with a so-called temporary score of importance noted stemp (SIGN (Mnew)) initialized to 0.

Then the 3D comparison module of the determination device 3 compares the signature SIGN (Mnew) of the electronic message Mnew with the signatures recorded in the reference base 4, with a view to identifying one or more signatures of the reference base 4 having a similarity with the signature SIGN (Mnew). More specifically, it searches in the reference base 4 if it contains one or more signatures having at least one element common with the signature SIGN (Mnew) (test step F40). This can be done by examining each line of the base 4 and comparing one by one the elements of the signature recorded in this line with the elements of the signature SIGN (Mnew).

If no signature is found in the reference base 4 during the search step F40 (response no to the test step F40), the process stops (step F50) and the device 3 for determining is not unable to assign a priority level to the Mnew email message.

If the 3D module identifies at least one signature in the reference base 4 sharing at least one element with the Mnew signature (answer yes at step F40), the second determination module 3E of the determination device 3 determines a priority level note

P (Mnew) of the new electronic message from the level of importance associated in the base 4 with reference to said at least one identified signature.

By way of illustration, in the example envisaged in FIG. 4, the 3D module identifies in the reference base 4, during step F40, three signatures having similarities with the signature SIGN (Mnew) of the message Mnew, namely the signature SIGN2 = (U2, W2, W4, T1) associated with a level of importance 1, the signature SIGN3 = (U2, W5, T3) associated with a level of importance 0 and the signature SIGN5 = (U4, W1 , W2, T4) associated with a level of importance 0.

In the embodiment described here, the module 3E determines for each signature identified during step F40, a degree of similarity with the signature SIGN (Mnew) (step F60). To determine this degree of similarity, the module 3E examines here how many elements the signature SIGN (Mnew) has in common with each of the signatures SIGN2, SIGN3 and SIGN5 identified in the base and having similarities with the signature SIGN (Mnew).

We denote by δ the degree of similarity estimated between a signature SIGN of the base 4 of reference and the signature SIGN (Mnew). In the illustrative example considered here:

- ô (SIGN2, SIGN (Mnew)) = 33% (one element in common on the three elements of the signature SIGN (Mnew));

- 5 (SIGN3, SIGN (Mnew)) = 66% (two elements in common on the three elements of the SIGN (Mnew) signature); and - ô (SIGN5, SIGN (Mnew)) = 33% (one element in common on the three elements of the signature SIGN (Mnew)).

The determination module 3E selects from among the signatures SIGN2, SIGN3 and SIGN5, the signature having the highest degree of similarity with the signature SIGN (Mnew). In the illustrative example considered here, it is the signature SIGN3.

In the embodiment described here, the module 3E checks whether the degree of similarity 5 (SIGN3, SIGN (Mnew)) is greater than a predetermined threshold THR1 (THR1 = 50% here).

If this is the case, the module 3E determines that the signature SIGN3 has a sufficient degree of similarity with the signature of the message SIGN (Mnew), and assigns to the electronic message Mnew as priority level P (Mnew), the level of importance associated in the base 4 with reference to the signature SIGN3 (step F70). In the illustrative example considered here, it therefore associates with the electronic message Mnew the level of importance 1 (important level).

Otherwise, the module 3E determines that the signature SIGN3 does not have a sufficient degree of similarity with the signature of the message SIGN (Mnew) to be able to determine a reliable priority level for the message Mnew from the associated level of importance. to this SIGN3 signature. In this case, in the embodiment described here, it does not assign any priority level to the Mnew message, and the process stops.

The determination device 3 repeats steps F20 to F70 for each new electronic message received by the electronic messaging tool 2 and intended for the user U.

It is assumed below that the electronic message Mnew has been opened and read by the user U and that the user U has replied to this message.

Following these various actions carried out by the user U on the message Mnew (and which constitute a processing of the message within the meaning of the invention), the update module 3F obtains from the electronic messaging tool 2 the time taken by user U to execute each of these three actions, in other words:

- the time To (Mnew) of opening the Mnew message;

- the time Tf (Mnew) for reading (or focusing) the Mnew message; and - the response time Tr (Mnew) to the message Mnew.

Such execution times can be easily obtained or even estimated by the module 3F as indicated previously for the construction device 5 from information recorded by the tool 2 (instant of reception of the message, instant of sending of a response , instant of opening of the message, and / or instant of change of focus).

It should be noted that by way of illustration, it is assumed here that the three aforementioned actions have been carried out by the user on the Mnew message. However, as a variant, only part of these actions may have been carried out (for example opening and reading), in which case only the times corresponding to the actions carried out are taken into account by the 3F module (in the previous example , times To (Mnew) and Tf (Mnew)).

Then the module 3F here updates the statistics previously calculated in step E10 by the construction device 5 taking into account the execution times To (Mnew), Tf (Mnew) and Tr (MNew) obtained, namely:

- the average opening time To_m of the messages processed by the user U and the standard deviation σο;

- the average time Tf_m of reading (or focus) of the messages processed by the user U and the standard deviation of; and - the average response time Tr_m of the messages processed by the user U and the standard deviation gold.

From these statistics, the 3F module evaluates for the electronic message Mnew and for each of the opening, reading and response actions performed on this message, a score associated with this action.

More precisely, in the example envisaged here, it evaluates for the message Mnew:

- a score so (Mnew) of importance associated with the action of opening the Mnew message;

- an important score sf (Mnew) associated with the action of reading the Mnew message; and - an important score sr (Mnew) associated with the response action to the message Mnew.

In the embodiment described here, the module 3F, like the module 5A, estimates each score of importance associated with an action for the message Mnew by comparing the time taken by the user U to perform this action on the message Mnew with respect to the corresponding average time and standard deviation evaluated by module 3F. It does this in the same way as module 5A.

As mentioned above, if one of the actions has not been performed by user U on the Mnew message, in this case no score is evaluated for this action.

The 3F module then updates the temporary stemp score (SIGN (Mnew)), associated with the signature of the Mnew message, by calculating a weighted sum of the scores so (Mnew), sf (Mnew), sr (Mnew) evaluated for the Mnew message (if a score has not been evaluated for a given action, only the evaluated scores are averaged). In the embodiment described here, the weighted sum calculated by the module 3F is an average of the scores so (Mnew), sf (Mnew) and sr (Mnew).

The 3F module proceeds in the same way for each new message received by the messaging tool and processed by the user U. If two messages correspond to the same signature, the temporary stemp score associated with this signature is updated by averaging the temporary scores of the two messages.

Then upon detection of a predetermined event, the module 3F updates the reference base 4 with the signatures of the new messages it has just processed and the temporary scores evaluated for these signatures (step F80). By way of illustration, we consider here four distinct signatures of new messages SIGN (Mnewl), SIGN (Mnew2), SIGN (Mnew3) and SIGN (Mnew4) with which the module 3F updates the reference base 4.

It is noted that different events can trigger the updating of the reference base 4. For example, such an event can be the detection by the module 3F of updating of a determined time (for example a determined time of the day ) or the detection of a closure of the messaging tool 2, etc.

The update of the reference base 4 is carried out by the module 3F in the following manner, for each signature SIGN (Mnewj), j = l, ..., 4, for which it has updated the temporary score since the last update of the reference base 4:

(1) The 3F module evaluates an overall score s (SIGN (Mnewj)) associated with the signature SIGN (Mnewj) from the temporary score stemp (SIGN (Mnewj)) associated with this signature, and if the signature SIGN (Mnewj) is already present in the reference base 4, from the global score s (SIGN (Mnewj)) associated in the reference base 4 with the signature (it averages the temporary score and the global score reported in the reference base 4).

(2) Then the 3F module estimates a level of importance of the messages corresponding to the SIGN signature (Mnewj) by comparing the global score s (SIGN (Mnewj)) thus evaluated with the THR-IMP threshold. It does this in the same way as module 5A: the importance level PL (SIGN (Mnewj)) is chosen by the estimation module 3F from the values IMP and NON-IMP. The assignment by module 3F of one or other of the IMP and NON-IMP values to the Mnew message depends on whether its overall importance score s (Mnew) is higher or lower than the THR-IMP threshold:

- if s (SIGN (Mnewj))> THR-IMP: PL (SIGN (Mnewj)) = IMP;

- otherwise: PL (SIGN (Mnewj)) = NON-IMP.

(3) The 3F module then updates the reference base 4 with the importance level PL (SIGN (Mnewj)), the global score s (SIGN (Mnewj)) and the SIGN signature (Mnewj) if the latter is not already present in the reference base 4. This update consists in adding to the reference base 4 a line associating the signature SIGN (Mnewj) at the level of importance PL (SIGN (Mnewj)) and the score s (SIGN (Mnewj)) if a line associated with the signature SIGN (Mnewj) does not already exist in the reference base 4. If a line associated with the SIGN signature (Mnewj) already exists in the reference base 4, the 3F module updates the level of importance and the overall score associated with this signature with the level of importance PL (SIGN ( Mnewj)) and the overall score s (SIGN (Mnewj)).

(4) Following the updating of the reference base 4, the module 3F resets to zero the temporary temp scores (SIGN (Mnewj)) of the SIGN signatures (Mnewj) that it has just updated.

If a line associated with the signature SIGN (Mnewj) in the base 4 of reference already exists, the module 3F updates the base 4 of reference with the new level of importance PL (SIGN (Mnewj)) determined if this one is different from the level of importance reported in the baseline 4 and with the new global score s (SIGN (Mnewj)).

In the embodiment described here, the construction device 5, the determination device 3 and the reference base 4 are integrated in the computer 1 and in the electronic messaging tool 2. As a variant, the construction device 5 can be located on a remote server, as can the reference base 4 and be accessible via for example the NW network, by the electronic messaging tool 2 and more particularly by its device 3 determination.

In addition, in the embodiment described here, three particular actions were considered carried out on an electronic message to deduce therefrom the level of importance of this message, namely the opening and reading of this message, and the response to this message. Of course, this example is not limitative of the invention and other actions can be considered to replace or in addition to these actions, such as for example, the deletion of a message by the user, or its transfer to another user, etc.

Advantageously, thanks to the determination made possible by the invention of a priority level for each new message received by the user U via his electronic messaging tool, it is possible to envisage sorting the user's messages according to this level of priority, and where applicable the application of differential treatment.

For example, user U can determine a set of rules to be applied to new electronic messages received as a function of the priority level determined for these new messages. Such rules stipulate, for example, to display messages associated with a "high" priority level first, to hide messages associated with a "secondary" priority level so as not to unnecessarily overwhelm the user U with information and take the risk of not seeing important information, activate notification of new incoming messages only if these messages correspond to a “high” priority level, send a reminder to user U when a message associated with a “high” priority level has not been opened by the user within a predetermined period or has not been answered by the user U after a certain period, etc.

In the embodiment described here, only two levels of importance and possible priority for electronic messages have been considered, namely 1 (important) or 0 (secondary). Of course, it is possible to introduce greater granularity by considering levels of importance and intermediate priority (eg message "secondary", "moderately important", "important", and "very important"). As previously described, the electronic messaging tool 2 can then apply different procedural rules to each message received by the user according to these different priority levels, such as for example:

- for a message associated with a “secondary” priority level: hide the notification of receipt of the message, and automatically move it to a specific directory;

- for a message associated with a “moderately important” priority level: hide the notification of receipt of the message, and leave it in the inbox;

- for a message associated with an “important” priority level: activate the notification of receipt of the message, and automatically assign it a specific category representative of its importance (for example a color associated with a label); and - for a message associated with a “very important” priority level: activate the notification of receipt of the message, issue an alarm on the computer 1 of user U, automatically assign to the message a specific category representative of its importance and display a reminder periodically until the message has been opened and read by user U.

Claims (15)

1. Method for constructing a reference base (4), intended to be used by an electronic messaging tool (2) to determine a priority level of an electronic message addressed to a user, said construction method comprising: - for each electronic message of a first plurality of electronic messages previously received and processed by the user: o an evaluation step (E20), for each action of a plurality of predetermined actions likely to have been carried out on the electronic message, of a score associated with this action from a time taken by the user to perform said action on said electronic message; a step (E40) of determining a signature of the electronic message formed of a predetermined set of elements extracted from the electronic message; - for each determined signature corresponding to at least one electronic message from said first plurality of electronic messages: o an estimation step (E50), of a level of importance of the messages corresponding to said signature, by comparing with at least a predetermined threshold, a so-called global score determined for said signature and resulting from a weighted sum of the scores evaluated for each message corresponding to said signature and associated with said plurality of actions; o a step (E60) of storing, in the reference base, in association with said signature, the estimated level of importance. 2. Construction method according to claim 1 wherein during the storage step (E60), the overall score determined for the signature is stored in the reference base in association with said signature and the estimated level of importance. 3. Construction method according to claim 1 or 2 wherein said plurality of predetermined actions comprises at least: - an opening of the electronic message; - a reading of the electronic message; and - a response to the electronic message. 4. Construction method according to claim 1, in which the score associated with a predetermined action is evaluated by comparing the time taken by the user to perform this action on the electronic message with respect to an average value of this time calculated on a second plurality of electronic messages previously received and processed by the user. 5. Construction method according to any one of claims 1 to 4 in which said predetermined set of elements from which the signature of the electronic message is formed comprises at least: - a sender of the electronic message; and / or - at least one keyword extracted from an object and / or from a body of the electronic message. 6. Construction method according to any one of claims 1 to 5 wherein the level of importance is selected from at least two values comprising a value representative of a signature of an important electronic message and a value representative of a signing a secondary email message. 7. Method for determining a priority level of an electronic message addressed to a user, said method comprising: A step for obtaining (F10) a reference base constructed using a construction method according to any one of claims 1 to 6 from a first plurality of electronic messages previously received and processed by the user via an electronic messaging tool; - following the reception (F20) by the electronic messaging tool of a new electronic message addressed to the user: a step (F30) of determining a signature of the new electronic message, said signature being formed of elements extracted from the new electronic message and corresponding to said predetermined set of elements; a step (F40) of comparing the signature of the new electronic message with the signatures stored in the reference base; and a step (F70) of determining a priority level of the new electronic message from at least one level of importance associated in the reference base with at least one signature having a similarity with the signature of the new message electronic. 8. Determination method according to claim 7, in which the step of determining the priority level of the new electronic message comprises: - searching (F40) in the reference base for at least one signature having at least one element common with the signature of the new electronic message; - the determination (F60), for each signature identified in the reference base during the search, of a degree of similarity with the signature of the new electronic message; the priority level of the new electronic message being determined from the level of importance associated with the signature identified in the reference base having the highest degree of similarity with the signature of the new electronic message. 9. Determination method according to claim 7 or 8 further comprising: A step of evaluation, for at least one action of said plurality of predetermined actions, of a score associated with this action from a time taken by the user to perform this action on the new electronic message; and a step of updating a so-called temporary score associated with the signature of the new electronic message with a weighted sum of the temporary score and the scores evaluated for said new message and associated with said at least one action; and - upon detection of a predetermined event, a step of updating the reference base comprising: o the evaluation of an overall score associated with the signature of the new message from the temporary score associated with this signature, and if the signature is already present in the reference base, of an overall score associated in the reference base to the signature ; o estimating the level of importance of the messages corresponding to the signature of the new message by comparing the overall score evaluated with said at least one predetermined threshold; and o updating the reference level of the level of importance and the overall score associated with the signature. 10. Determination method according to any one of claims 7 to 9 further comprising a step of processing the new electronic message, said processing being selected according to the priority level determined for this new electronic message. 11. Computer program (PROG5, PROG3) comprising instructions for the execution of the steps of the method of constructing a reference base according to any one of claims 1 to 6 or of a method of determining according to any one of claims 7 to 10 when said program is executed by a computer. 12. Recording medium (8) readable by a computer on which a computer program is recorded according to claim 11. 13. Construction device (5), configured to construct a reference base (4) intended to be used by an electronic messaging tool to determine a priority level of an electronic message addressed to a user, said device comprising: Modules activated for each electronic message of a first plurality of electronic messages previously received and processed by the user, said modules comprising: o an evaluation module (5A), configured to evaluate for each action of a plurality of predetermined actions performed on the electronic message, a score associated with this action from a time taken by the user to perform said action on said electronic message; a module for determining (5B) a signature of the electronic message, configured to extract a predetermined set of elements from the electronic message and form said signature of the electronic message from the elements extracted; Modules activated for each determined signature corresponding to at least one electronic message from said first plurality of electronic messages, said modules comprising: o an estimation module (5C) of a level of importance of the messages corresponding to said signature, configured to estimate said level of importance by comparing with at least a predetermined threshold, a so-called global score determined for said signature and resulting a weighted sum of the scores evaluated for each message corresponding to said signature and associated with said plurality of actions; o a storage module (5D), configured to store in the reference base, in association with said signature, the estimated level of importance. 14. Device for determining (3) a priority level of an electronic message addressed to a user, said device comprising: - an access module (3A), configured to access a reference base constructed by a construction device according to claim 13 from a first plurality of electronic messages previously received and processed by the user via a email ; - a reception module (3B), configured to detect the reception by the electronic messaging tool of new electronic messages addressed to the user; A plurality of modules (3C-3E), activated following the detection by the reception module of the reception of a said new electronic message addressed to the user, said plurality of modules comprising: a first determination module (3C), configured to determine a signature of the new electronic message, said signature being formed from elements extracted from the new electronic message and corresponding to said predetermined set of elements; o a comparison module (3D), configured to compare the signature of the new electronic message with the signatures stored in the reference database; and a second determination module (3E), configured to determine a priority level of the new electronic message from at least one level of importance associated in the reference base with at least one signature having a similarity with the signature of the new email message. 15. An electronic messaging tool (2) comprising a determination device (3) according to claim 14 and a construction device (5) according to claim 13.