Method and software product for identifying unsolicited emails

• US 8,321,512 B2
• Filed: 08/19/2004
• Issued: 11/27/2012
• Est. Priority Date: 08/22/2003
• Status: Expired due to Fees

• Current Assignee: Geobytes Incorporated
• Original Assignee: Geobytes Incorporated
• Inventors: McElligott, Adrian
• Primary Examiner(s): Follansbee, John
• Assistant Examiner(s): Woolcock, Madhu
• Application Number:
  US10/922,010
• Publication Number:
  US 20050044160A1
• Time in Patent Office: 3,022 Days
• Field of Search: 709/204, 709/205, 709/206, 709/207
• US Class Current: 709/206
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases

Abstract

A method and software product for detecting unsolicited emails, e.g. spam, involves altering the case of at least some symbols comprising an email user'"'"'s email address according to a predetermined criteria prior to transmitting an email message. The altered case sequence of the email user'"'"'s address is stored in a database. Subsequently, as email'"'"'s are received in the email user'"'"'s mailbox their intended recipient addresses are processed to determine if they include symbols whose case sequence, i.e. uppercase and lowercase, matches one of the sequences that was previously stored. If no match is found then the incoming email is treated as potentially constituting spam and is handled as such. Embodiments of the invention take advantage of a property of most Internet post office email servers being that they are generally case insensitive in respect of the symbols that make up an email address.

Claims

1. A computer-implemented method for filtering email messages having an intended recipient email address identifying a user'"'"'s mailbox, the method including, the steps of:

receiving an email message on a computer sent to or from an electronic mail application;

identifying a pattern of uppercase and lowercase letters used to form the intended recipient email address;

generating an email message validation pattern based on the identified pattern;

comparing the email message validation pattern to a stored email message validation pattern;

providing filtering instruction to the electronic mail application for the email message based on the comparison;

wherein the received email message comprises a reply to a prior email message sent from a sender'"'"'s email address that is the intended recipient email address of the received email message, the method further including the additional steps of (a) applying case alterations to letters used to form the sender'"'"'s email address of the prior email message producing a pattern of uppercase and lowercase letters used to form the sender'"'"'s email address, (b) generating the email message validation pattern based on the pattern of uppercase and lowercase letters symbols used to form the sender'"'"'s email address, and (c) storing the email message validation pattern for subsequent reference during said comparing step; and

wherein the sender'"'"'s email address comprises a local portion and a domain portion and wherein the email message validation pattern stored in step (c) comprises the pattern of uppercase and lowercase letters used to form the local portion of the sender'"'"'s email address produced during step (a).

2. A computer-implemented method according to claim 1, wherein the step of comparing the email message validation pattern to a stored validation pattern includes determining if a case sequence of at least a portion of the intended recipient email address corresponds to a previously stored case sequence.

3. A computer-implemented method according to claim 1, wherein the step of comparing the email message validation pattern to a stored validation pattern further includes determining if a domain name portion of a sender email address of each of the email messages corresponds to a previously stored domain name.

4. A computer-implemented method according to claim 3, including determining if the domain name portion of the sender email address is a case insensitive match with a previously stored domain name.

5. A computer-implemented method according to claim 1, wherein a plurality of patterns of uppercase and lowercase letters used to form the sender'"'"'s email address are produced in step (a) and further comprising the additional steps of (i) performing a readability analysis on each one of the plurality of patterns, and (ii) selecting one of the plurality of patterns that is most readable for use in step (b).

6. A computer-implemented method according to claim 1, wherein the email message validation pattern stored in step (c) comprises a copy of the sender'"'"'s email address after applying the case alterations.

7. A computer-implemented method according to claim 1, wherein the email message validation pattern stored in step (c) comprises a binary number.

8. A computer-implemented method according to claim 1 wherein the sender'"'"'s email address comprises a local portion and a domain portion and wherein the email message validation pattern stored in step (c) comprises the letters used to form the domain portion of the sender'"'"'s email address produced during step (a).

9. A computer-implemented method according to claim 1 further including the step of deleting the email message validation pattern stored in step (c) after a predetermined time.

10. A computer-implemented method according to claim 1 wherein the step of applying case alterations to letters comprising a the sender'"'"'s email address produces a pattern of uppercase and lowercase letters used to form the sender'"'"'s email address which is in turn used to form an email hyperlink for inclusion in web pages.

11. A computer-implemented method according to claim 1, wherein the step of comparing the email message validation pattern to a stored validation pattern is performed by software running on the computer on which the electronic mail application which is used to read mail from the user'"'"'s mailbox resides.

12. A computer-implemented method according to claim 1, wherein the step of comparing the email message validation pattern to a stored validation pattern is performed by software running on an Internet email server in communication with a computer used to read mail from the user'"'"'s mailbox.

13. A computer configured to execute instructions embodied in a non-transitory computer readable medium of the computer, the instructions being executable by the computer to perform a series of steps, including

receiving an email message sent to or from an electronic mail application;

identifying a pattern of uppercase and lowercase letters used to form an intended recipient email address;

generating an email message validation pattern based on the identified pattern;

comparing the email message validation pattern to a stored validation pattern;

providing filtering instruction for the email message based on the comparison;

applying a computer-implemented anti-Spam filter to the email message;

wherein the received email message comprises a reply to a prior email message sent from a sender'"'"'s email address that is the intended recipient email address of the received email message, the method further including the additional steps of (a) applying case alterations to letters used to form the sender'"'"'s email address of the prior email message producing a pattern of uppercase and lowercase letters used to form the sender'"'"'s email address, (b) generating the email message validation pattern based on the pattern of uppercase and lowercase letters symbols used to form the sender'"'"'s email address, and (c) storing the email message validation pattern for subsequent reference during said comparing step; and

wherein the sender'"'"'s email address comprises a local portion and a domain portion and wherein the email message validation pattern stored in step (c) comprises the pattern of uppercase and lowercase letters used to form the local portion of the sender'"'"'s email address produced during step (a).

14. A computer according to claim 13, further including instructions to determine if a case sequence of at least a portion of the intended recipient email address corresponds to a previously stored case sequence.

15. A computer according to claim 13, including instructions to determine if a domain name portion of a sender email address of the email message corresponds to a previously stored domain name.

16. A computer according to claim 15, wherein the instructions to determine if a domain name portion of the sender'"'"'s email address corresponds to a previously stored domain name includes instructions to determine if a domain name portion of the sender'"'"'s email address is a case insensitive match with a previously stored domain name.

17. A computer according to claim 13, wherein a plurality of patterns of uppercase and lowercase letters used to form the sender'"'"'s email address are produced in step (a) and further comprising instructions to (i) perform a readability analysis on each one of the plurality of patterns, and (ii) select one of the plurality of patterns that is most readable for use in step (b).

18. A computer according to claim 13, including instructions to store the email message validation pattern stored in step (c) in the form of a binary number.

19. A computer according to claim 13, wherein the sender'"'"'s email address comprises a local portion and a domain portion and wherein the email message validation pattern stored in step (c) comprises the letters used to form the domain portion of the sender'"'"'s email address produced during step (a).

20. A computer according to claim 13 including instructions to delete the email message validation pattern stored in step (c) after a predetermined time.

21. A computer-implemented method for filtering email messages having an intended recipient address identifying a user'"'"'s mailbox, the method including, for each of said messages, the steps of:

receiving an outgoing email message at a first computer;

applying case alterations to letters used to form the intended recipient email address of the outgoing email message producing a pattern of uppercase and lowercase letters used to form the recipient email address and generating an email message validation pattern based on the pattern of uppercase and lowercase letters used to form the recipient email address;

wherein the recipient email address comprises a local portion and a domain portion and wherein the email message validation pattern comprises a pattern of uppercase and lowercase letters used to form the local portion of the recipient email address;

storing the email message validation pattern in association with the intended recipient email address on the first computer for subsequent reference;

receiving a reply incoming email message from a sender'"'"'s email address that is the intended recipient email address;

comparing the stored email message validation pattern to an email message validation pattern generated based on a pattern of uppercase and lowercase letters used to form the sender'"'"'s email address in the reply incoming email message; and

providing filtering instruction for the email message based on the comparison.

22. A computer-implemented method according to claim 21 wherein the validation pattern comprises a code based upon a case sequence of a sender'"'"'s email address.

23. A computer-implemented method according to claim 22 wherein the code comprises a binary number.

24. A computer-implemented method according to claim 21 wherein the validation pattern is retained by a second computer that is remotely located.

25. A computer-implemented method according to claim 24 wherein the validation pattern is generated or otherwise provided by the second computer that is remotely located.

26. A computer-implemented method according to claim 21 wherein the validation pattern is used by a third computer that is remotely located to ascertain whether a future email is unsolicited.

27. A computer-implemented method according to claim 26 wherein the future email is blocked if it is determined to be unsolicited.

28. A computer-implemented method according to claim 26 wherein the future email is further processed to determine whether it is Spam if the future email is determined to be unsolicited.

29. A computer-implemented method according to claim 21 wherein the validation pattern comprises a case sequence that is retained in a database along with a date of creation of the case sequence and an expiration date of the case sequence.

30. A computer-implemented method according to claim 29 wherein details of an addressee associated with the intended recipient email address are also stored in the database with each corresponding case sequence.