CN1346469A - Method and system for interrogating the internet - Google Patents

Abstract

A method and system for identifying an electronic mail server to which a remote user belongs includes providing a remote access mail client accociated with an access database containing records of servers supporting a specified electronic mail protocol or protocols, requiring the user at a remote computer with a browser to input his electronic mail address and log-in password, parsing the mail address to obtain a presumed domain name of the user's server, interrogating the access database to determine whether it contains a record of a server corresponding to the presumed domain name; and retrieving the record of any corresponding server thus identified as the server to which the user may belong. If the database contains no record of a corresponding server, the domain name is assumed to be the server and is checked for the user's mail, after which the MX record and IP address are requested from the DNS database and are checked, the full list of host names for the presumed domain name is requested by DNS zone transfer and any host supporting the specified protocol(s) are checked and, if necessary, the NIC-allocated IP address block of the presumed domain name is finally obtained from the WHOIS server and is scanned. A search engine associated with the specified protocol or protocols performs the searching under the direction of the mail client and database.

Description

Method and system for querying the Internet

Description of the invention

The present invention relates to a method and system for interrogating the Internet to identify a server to which a remote user belongs, without the user being able to specify the server.

For those Internet users who travel for business or leisure, it is often necessary to be able to establish a connection with the server to which the user belongs at a long distance, for example, to retrieve e-mail.

Software systems known as remote access mail clients are known for retrieving mail for a remote user from the user's email server. However, these known remote access mail clients require the user to specify the associated email server by providing the server name and the numeric Internet Provider (IP) address.

If the user cannot specify a server in this way, the user will not be able to retrieve e-mail remotely. The user therefore has to carry relevant information with him. And because this information is not the kind of information that is easy to remember, the user may have to carry this information in written form.

If the information is stored in the user's memory, it may be forgotten or recalled incompletely; if it is stored in the form of a written list, it may be lost or misplaced, and there is a risk of falling into the hands of others.

Furthermore, many users of the Internet are not tech-savvy, lacking a solid knowledge or understanding of technical terms and information related to the Internet.

Therefore, it is an object of the present invention to provide a method and system capable of identifying the server to which a remote user belongs while only requiring the user to provide basic, easy-to-remember information.

Thus, in one aspect, the present invention provides a method of identifying a server to which a remote user belongs without the user being able to specify the server, the method comprising the steps of: providing an access database including the email addresses supporting a particular email protocol or suite of protocols server's records; ask the user to give an e-mail address and the user's registration password; analyze the e-mail address to identify and remove the user identifier from the e-mail address, thereby obtaining a hypothetical domain name of the user's server; interrogate the access database , to determine whether it contains a record for the server corresponding to the hypothetical domain name; and retrieve any corresponding server records, thus identifying the server to which the user belongs.

If the access database does not include a corresponding server record, the method may include the following further steps: assuming that the domain name is the user's server; checking the user's mail at the domain name; if the domain name responds with the mail, then Identify the domain name as the user's server.

If the access database does not include a corresponding server record and the domain name does not respond to the email, the method may include the further step of sending a mail exchange (MX) record query to the Internet Domain Name System (IDS) associated with the hypothetical domain name DNS) database; list the responses received from the DNS database; check these responses in turn to determine whether the predetermined port or port group associated with the predetermined protocol or protocol group is open or closed; and identify the response with the open port or port group as The user's server.

The method may also include the further steps of: obtaining the Internet provider (IP) address of the MX record; checking the open or closed status of the predetermined port or port group to seek a predetermined block of host IP addresses; Write all the IP addresses with the predetermined open port or port group status; use the user address and password to query the stored IP addresses in the temporary database; identify a successful IP address as the user's server.

If the user server is not identified in the response of the DNS database, the method may include the following further steps: via DNS range conversion, a list of all hostnames is required for the hypothetical domain name; the predetermined port status of the listed hostnames is checked in turn. open or close; and identify the host with open port status as the user server.

If the above steps of the method fail to identify the user's server, the method may include the following further steps: retrieving the IP address block that has been assigned to the hypothetical domain name by the Network Information Center (NIC); checking The predetermined port or port group of the IP address in the block is open or closed; store all IP addresses with open port states in the access database; query the stored IP addresses in turn with the user address and password; and identify A successful IP address serves as the user's server.

Advantageously, the method may comprise the step of updating the access database with records of previously unrecorded servers identified as customer servers or identified as supporting a predetermined protocol or set of protocols.

A preferred embodiment of the method includes the steps of retrieving the user's electronic mail from a server identified as the user's server and forwarding the mail to the remote user.

In another aspect, the present invention provides a system for identifying a server to which a remote user belongs without the user being able to specify the server, comprising: an access database including records of servers supporting a predetermined electronic mail protocol or suite of protocols; and A remote access mail client software, which is related to the database and can access the Internet domain name system (DNS) database and a search engine related to the protocol or protocol suite; in the system, the remote access mail client is configured software to ask the user to give the user's e-mail address and password, analyze the e-mail address to identify and remove the user identifier from the e-mail address, thereby obtaining a hypothetical domain name of the user's server, interrogate the access database, to determine whether it contains a record for a server corresponding to the hypothetical domain name, and to retrieve any corresponding server records, thus identifying the server to which the user belongs.

Preferably, wherein remote access mail client software is configured, if the access database does not include a corresponding server record, it is assumed that the hypothetical domain name is the user's server, and the user's mail is checked in the domain name; if the When the domain name responds with the mail, the domain name is identified as the user's server.

If the database does not contain a record for the corresponding server and the hypothetical domain name does not respond to user mail, the remote access mail client software is configured to issue a mail exchange (MX) record query to the DNS associated with the hypothetical domain name ( DNS) database, listing responses from the DNS database, examining these responses in turn to determine whether a predetermined port or port group associated with the protocol or protocol group is open or closed, and identifying a response with an open port or port group as the user's server.

The remote access mail client software configured therein can also obtain the IP address of the MX record, check the opening or closing status of the predetermined port or port group, seek the predetermined block of the host IP address, and store all the opened ports. IP address; use the user address and password to inquire the stored IP address in turn; identify a successful IP address as the user's server.

If the user's server is not identified in the DNS database's response, the remote access mail client software configured therein so that, via DNS interval translation, a full list of hostnames is required for the hypothetical domain name; check the listed hostnames in turn The predetermined port state is open or closed, and the host with the open port state is identified as the user server.

If the foregoing actions of the remote access mail client fail to identify the user's server, the remote access mail client is configured to retrieve, through the network information center (NIC), a block of IP addresses that has been Assigned to the hypothetical domain name; check whether the predetermined port or port group is open or closed; store all IP addresses with open port status in the access database; use the user address and password to query the stored IP addresses in turn , and identify a successful IP address as the user's server.

Advantageously, the remote access mail client software is configured such that a record is written in the access database for any previously unrecorded server identified as a user server.

In a preferred embodiment of the system, the remote access mail client software is configured to retrieve the user's electronic mail from any server identified as the user's server and forward the mail to the remote user.

In order to make the present invention easier to understand, its embodiment is described below with reference to the accompanying drawings, as an example, wherein:

1 is a schematic diagram of a system embodying the present invention for retrieving e-mail from a user's e-mail server for a remote user;

Figure 2 is a table of the database contained in Figure 1;

3A and 3B together form a flowchart illustrating the method of retrieving electronic mail implemented by the system of FIG. 1 .

Referring first to FIG. 1, a system embodying the present invention for retrieving e-mail from a user's e-mail server for a remote user includes a web-based e-mail application or remote access mail client software 1 that runs A more detailed description will be given below. Associated with the remote access mail client software 1 is a dynamic access database 2 that includes records of servers that support a particular email protocol or suite of protocols, here Post Office Protocol (POP3) and Internet Message Access Protocol (IMAP4) .

The remote access mail client software 1 can access the Internet widely, especially the domain name system (DNS) database 3, which is related to domain names and numerical IP addresses; Blocks of IP addresses assigned to domains, organizations and companies; and access to the POP3/IMAP4 search engine5.

It is assumed that a user wishing to retrieve his e-mail has remotely available a computer 6 equipped with Internet access and a browser 7 through which the user can use the remote access mail client software 1 . For example, the computer 6 may be any suitable computer and is served by any Internet Service Provider (ISP) at the hotel or office location to which the user travels.

The user's email server 8 is shown in Figure 1 as phantom lines, which server supports POP3/IMAP4 and is recognized and contacted by the remote access mail client software.

Figure 2 depicts a database 2 implementing the invention. It can be seen that the database 2 is divided into a first table T1 and a second table T2. The first table T1 contains a series of user records, and each user record contains three items, namely: use the user email address of the system, the identification number (IP address) and the error flag number of the POP3/IMAP4 server to which the user belongs, wherein, The error flag number can be 0-6 and its purpose is described below.

The second table T2 contains domain records, each domain record containing two items, namely: a domain name and the identification number (IP address) of the email server associated with that domain name.

In Figure 2, tables T1 and T2 each contain an example of a user and domain record.

With regard to the system of FIG. 1 realizing the method of identifying the server 8 of the user and retrieving the user's e-mail, an overview will be given first, and then a more detailed description will be made according to FIGS. 3A and 3B.

In summary, the method requires the user to first log into the Internet Service Provider (ISP) at the computer 6 and then access the remote access mail client software 1 through the browser 7 . Based on the remote access mail client software 1 protocol, the system's home page invites the user to simply type in the user's e-mail address and login password, and then press ENTER. Thus, the remote access mail client software 1 begins a series of steps in an attempt to identify the user server in use with the minimum information provided by the user. Based on the identification of the user's server, the remote access mail client software 1 provides the server with the user's new address and password to retrieve the user's mail and send it to the user at the computer 6 .

The method consists of three basic stages, which are performed sequentially according to the desired degree.

In the first step of the first stage, the remote access mail client software 1 parses the email address provided by the user and strips the user identification code from the address, based on the assumption that the user identification code in the address is the same as the user login password, and continues to run, The assumed user server domain name is thus obtained. The remote access mail client software 1 then interrogates the access database 2 with a user record indicating the user's server to determine whether the user is an existing user, and if not, whether the database contains the server domain name corresponding to the assumed user domain records.

If there is such a record, it is extracted from the access database and the user details are transmitted to the server thus identified to retrieve the user's mail and forward the mail to the user at computer 6 .

For example, suppose a user enters the email address "userid@aztech.com.sg". After checking whether there is a user record corresponding to the address, the remote access mail client software 1 strips the user identification code "userid" and checks the access database 2 to determine whether it contains the corresponding domain name "aztech.com.sg" domain record. If there is such a record, it identifies the user's server and can retrieve the user's mail and send it to computer 6.

In the second step of the first phase, the remote access mail client software 1 assumes that the domain name is the user server, and checks the domain name for the user mail, and if the user mail is retrieved, identifies the domain name as the user server, and Write a domain name record in the access database 2.

If the domain name does not respond with the mail, the remote access mail client software 1 sends a DNS query to check the MX record. Responses received from the DNS database 3 are listed by the remote access mail client software 1 in a sorted manner, since most email servers currently support the POP3/IMAP4 protocol, the basic assumption is that one of them will be the user's POP3/IMAP4 server , and the mail exchange server is also a POP3/IMAP4 server. Each response is checked to determine whether the port 110 and/or port 143 associated with the POP3/IMAP4 protocol is on or off. The user ID and login password are sent to any of these ports that respond to being open to retrieve user mail, and a record of any successful response is written to the access database 2. End the first stage of operation.

If the first stage of the method fails to identify the user server, the remote access mail client software 1 starts the second stage of the method, in its first step, first enumerating the IP addresses. This involves the remote access mail client software 1 obtaining the IP address of the MX record and checking the open or closed status of ports 110 and 143 for primary IP addresses 2 to 254 (eg addresses 203.120.164.2 to 203.120.164.254). All those IP addresses with open ports 110 and/or 143 are then checked to find any recorded user emails of successful hosts, which are then written into the access database 2.

If the enumeration of the IP address fails to identify the user server, the remote access mail client software 1 starts the second step of the second phase of the method, in which a list of all CANAME and/or HOST names is required from the transfer zone from the DNS database, Domain name to use for assumptions. Check the listed hostnames, look for open ports 110 and 143, and hostnames with open port status are written to the access database 2, and user emails are queried, and records of any successful hosts are written to the access database 2.

If the second stage of the method fails to identify the user's server, the remote access mail client software 1 begins the third and final stage, wherein the system extracts the IP address block, INETNUM, NETNUMER or NETBLOCK from the WHOIS (database about who's there) server , which is assigned by the Network Information Center (NIC) to a domain organization or company, and scans ports 110 and 143 for addresses in that block. Also, use all IP addresses with open port status to inquire about the recorded user emails with successful hosts written in the access database 2.

The entry of the user's server record in the access database 2, when and if the server is located, means that the system does not have to go through the same process again to find a user with the same presumed domain name, since in The first step of Phase 1 identifies the user server and access is almost instantaneous.

With reference to Figure 2, the operation of the system is described in detail, and the following steps are performed:

S1 According to the request of the home page, the user enters his email address and password on the computer 6.

S2 checks table 1 of database 2 to see if there is an existing user record. If there is such a record, confirm that the user is an existing user with the email server confirmed in its record, and the method goes to step 3. If not, the method goes to step S4.

S3 In this step, check the email of the user in use, if you get it, pass it to the user at the remote end, set the error flag to O and complete the process. If the user's mail is not obtained, such as because of a record error, the method proceeds to step S5. For example, user records may be incorrect due to changes to the user's server identification number.

S4 This step presents the terms and conditions of the system to a user who is not yet a user of the system. If the user accepts, at write step W1, his e-mail address is written to Table 1 to create a record for that user and the method proceeds to step S6. If the user does not accept the terms and conditions, the user goes to step R1 and returns to the system home page at step S1.

S5 In this step, the error flag in the user record in use in T1 is increased by 1. If the value of the error flag is less than or equal to 6, the method proceeds to step S6. If the error flag value is greater than 6, the method proceeds to step S7.

S6 This step strips the user identifier from the user email address from step S5 or W1 to obtain the assumed domain name, which is then checked against the domain record in table T2 to see if there is a corresponding domain record. If there is a corresponding domain record, the method goes to step S8. If not, the method goes to step S10.

S7 In this step, notify the manager that there are 6 failed attempts to get back the user's email, and the method goes to step S10.

S8 checks the user email with the server details contained in Table 2 for the user's assumed domain. If the mail is retrieved, the details of the corresponding server are written to Table 1 and Table 2, completing the process. If not, the method goes to step S9.

S9 updates table T1 of the database with a user error flag incremented by 1, and displays the message PLEASE TRY AGAIN LATER (please try again later). If the error flag has a value greater than 6, the method notifies the administrator via step S7.

S10 This step starts to query the Internet to determine the POP3/IMAP4 server that the user belongs to, such as still unknown, and first starts step S11.

S11 This step assumes that the assumed domain name is the server and checks it to find the user mail. If the attempt is successful, the server record is written to the user record and the domain database record, and the process terminates at step W2 of writing tables 1 and 2. If the attempt fails, check the DNS MX records. If this identifies the user server, the server record is written to tables 1 and 2 at write step W3 and the process terminates. If neither the assumed domain name nor the DNS MX record check identifies the user server, but the checked server supports POP3/IMAP4, at write step W4, the server details are written to the domain record in Table 2. The method goes to step S12.

S12 This step obtains the IP address of the MX record, passes the user ID and password, and starts the first scanning step S13.

S13 In this step, scan the MX IP address. If the user server is identified, at write step W5, the server record is written to the user and domain records in Tables 1 and 2, and the process terminates. If the scanning fails, in the write step W6, the addresses that fail but support POP3/IMAP4 are written into Table 2, and the method proceeds to step S14.

S14 This step requires DNS interval conversion of all hostnames in the domain. If the request is successful, the method proceeds to step S15. If it fails, the method goes to step S16.

S15 If the required range conversion is performed, the obtained host name is scanned and the user mail is checked. If one of the scanned hosts turns out to be a user server, at write step W1, a record for the server is written to the user and domain records of tables 1 and 2. If not, the failed but POP3/IMAP4 supported addresses are written into the database table 2 in the write step W8.

S16 Failure to identify the user server at step S14 leads to start of this step, which obtains the IP address block for the domain from the WHOIS server, scans the addresses and selects those addresses supporting the POP3/IMAP4 protocol, start of step S17.

S17 This step checks the addresses selected in step S16 for user mail, and in write step W9, any successful host records are written to the user and domain records in database tables 1 and 2. In write step 10, hosts that fail but support POP3/IMAP4 are written to the domain records in Table 2 of the database.

S18 Even if step S17 is still unsuccessful, the final step of the method terminates the user server search and sends an e-mail to notify the administrator of the system.

In the above method, the remote access mail client software 1 parses the input user address and password, and the POP3/IMAP4 search engine executes the search and accesses the database (SQL server) to start the POP3/IMAP4 search and update.

It will be appreciated that the described method of the present invention will have applications other than remote access to user email. However, the described method and system embodying the present invention have unique advantages for remote retrieval of electronic mail, namely, users do not need to carry all their technical information with them when they travel; there is no danger of such information falling into the hands of other people; Most users can reliably remember their own e-mail addresses and passwords, so there is no need to write anything down; users are not bothered by having to provide complex information that is known to POP3/IMP4 remote access mail clients Required by the software, it is used to provide the information of the remote user's mail.

The ease and convenience of using the system of the present invention allows traveling executives to stay in touch even if they are not very tech-savvy, or lose, or forget, at a distance, the information needed to establish access using known remote access mail clients. A secret list of server names and IP addresses.

It is clearer that the establishment of POP3/IMAP4 server database in the system implementing the present invention enables more efficient use of system and Internet resources.

Finally, it should be noted that if the user's email server does not support POP3/IMAP4 mail, the user enters an incorrect email address or password, or the user does not have access, the system implementing the invention may not recognize the user's server at all, which also precludes the use of existing Well-known remote access mail client software, such as EUDORA and INTERNETMAIL.

Claims (20)

1. A method for identifying an e-mail server to which a remote user belongs, and the user cannot specify the server, comprising the following steps: Provides access to a database that includes records of servers that support a particular email protocol or suite of protocols; requires users to give email addresses and user login passwords; analyzes email addresses to identify and remove users from email addresses identifier, thereby obtaining a hypothetical domain name for the user's server; interrogating the access database to determine whether it contains a record for the server corresponding to the hypothetical domain name; and retrieving any corresponding server records, thereby identifying the server to which the user belongs . 2. The method according to claim 1, comprising the steps of: if the access database does not include a corresponding server record, assuming that the domain name is the server; checking the domain name for the user email; if the domain name responds with the mail, the domain name is identified as the user's server. 3. The method of claim 2, if the access database does not include a corresponding server record and the domain name does not respond to the email, comprising the step of: sending a mail exchange (MX) record query to the hypothetical domain name Relevant Internet Domain Name System (DNS) database; List responses received from the DNS database; Check these responses in turn to determine whether ports associated with the predetermined protocol or protocol group are open or closed; Identify responses with open ports or port groups as The user's server. 4. The method of claim 3, comprising: obtaining the Internet Provider (IP) address of the MX record; checking the open or closed state of the predetermined port or port group for a predetermined block of host IP addresses; Store all IP addresses with open port status in the access database; use the user address and password to query the stored IP address; identify a successful IP address as the user's server. 5. The method according to claim 3, if the user server is not identified from the response of the DNS database, comprising the steps of: requesting a list of all hostnames for the hypothetical domain name through DNS interval conversion; checking the listed hosts in sequence The predetermined port state of the name is open or closed; identifying the host with the open port state as the user server. 6. The method according to claim 5, if the DNS database does not allow interval switching, comprising the following steps: through the Network Information Center (NIC), retrieving the IP address block, the IP address block has been assigned to the hypothetical domain name; Check whether the predetermined port or port group of the IP address in the block is open or closed; store all IP addresses with open port status in the access database; query each stored IP address with the user address and password; Identify a successful IP address as the user's server. 7. A method as claimed in any one of claims 2 to 6, comprising the step of updating the access database with records of previously unrecorded servers identified as customer servers or identified as supporting a predetermined protocol or protocol group. 8. A method as claimed in any preceding claim, including the step of retrieving the user's e-mail from a server identified as the user's server and forwarding the e-mail to the remote user. 9. A method according to any one of the preceding claims, wherein the database is divided into first and second tables, and comprises the step of entering in the first table user email address records and servers identified as corresponding servers Address records; enter domain name records and any server address records identified as corresponding servers in the second table. 10. A method according to any preceding claim, wherein the predetermined protocol or set of protocols is the Post Office Protocol (POP3) and/or the Internet Message Access Protocol (IMAP4). 11. A system for identifying a server to which a remote user belongs, and the user cannot specify the server, comprising: an access database including records of servers supporting a predetermined electronic mail protocol or protocol suite; and a remote access mail Client software, which is related to the database and can access the Internet Domain Name System (DNS) database and a search engine related to the protocol or protocol suite; in the system, remote access mail client software is configured to require users to Given the user's email address and password, the email address is analyzed to identify and remove the user identifier from the email address, thereby obtaining a hypothetical domain name for the user's server, querying the access database to determine if it contains A record for the server corresponding to the hypothetical domain name, and any corresponding server records are retrieved, thereby identifying the server to which the user belongs. 12. The system of claim 11, wherein remote access mail client software is configured to check the domain name assuming that the assumed domain name is the user's server if the access database does not include a corresponding server record to seek the user's mail; if the domain name responds with the mail, the domain name is identified as the user's server. 13. The system of claim 12, wherein remote access mail client software is configured to issue a Mail Exchange (MX) record query to a Domain Name System (DNS) database associated with the hypothetical domain name, listing the DNS database The responses are checked in turn to determine whether predetermined ports associated with the protocol or group of protocols are open or closed, and the server identifying the client has the response with the port or group of ports open. 14. The system according to claim 13, wherein remote access mail client software is configured to obtain the IP address of the MX record, check the open or closed status of the predetermined port or port group, and seek the IP address of the host Predetermined blocks store all IP addresses with open ports; use the user address and password to query the stored IP addresses in turn; identify a successful IP address as the user's server. 15. The system according to claim 14, wherein remote access mail client software is configured, through DNS interval conversion, for the hypothetical domain name requires a list of all host names, check whether the predetermined port status of the listed host names is open or Close, and identify the host with open port status as the user server. 16. The system of claim 15, wherein remote access mail client software is configured to retrieve, via a network information center (NIC), a block of IP addresses that has been assigned to the hypothetical domain name; check The predetermined port or port group is in the open or closed state; store all IP addresses with the open port state in the access database; use the user address and password to inquire in turn about the IP addresses with the open port state and identify a successful IP address as the user's server. 17. A system according to any one of claims 11 to 16, wherein remote access mail client software is arranged such that a record of a previously unrecorded server is written in the access database, the server being identified as A user server, identified as supporting a predetermined protocol or set of protocols. 18. A system as claimed in any one of claims 11 to 17, wherein remote access mail client software is arranged to retrieve the user's electronic mail from any server identified as the user's server, And pass the mail to the remote user. 19. A system according to any one of claims 11 to 18, wherein the database is divided into first and second tables, records of user email addresses and their corresponding servers are entered into the first table, domain names and The record of its corresponding server is entered into the second table. 20. A system according to any one of claims 11 to 19, wherein the predetermined protocol or set of protocols is the Post Office Protocol (POP3) and/or the Internet Message Access Protocol (IMAP4).

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