Method and device for processing electronic mail undesirable for user

• US 20050198142A1
• Filed: 02/19/2003
• Published: 09/08/2005
• Est. Priority Date: 02/22/2002
• Status: Active Grant

• Current Assignee: Access Company Limited
• Original Assignee: Access Company Limited
• Inventors: Yamakami, Toshihiko
• Granted Patent: US 8,176,125 B2
• Time in Patent Office: Days
• US Class Current: 709/206
• CPC Class Codes: G06Q 10/107 Computer-aided management of electronic mailing [e-mailing]
• CPC Class Codes: H04L 51/212 using filtering or selective blocking
• CPC Class Codes: H04L 51/23 Reliability checks, e.g. acknowledgments or fault reporting
• CPC Class Codes: H04L 51/48 Message addressing, e.g. address format or anonymous messages, aliases

Abstract

Emails are received and the received emails are classified and accumulated based on relay path information contained in the header of each email. For each of the classified groups, a judgment is made according to a judgment rule including at least (1) the number of received emails per unit time is a first threshold or more and (2) the number of emails having an invalid destination address is a second threshold or more. For emails included in a classified group satisfying at least a prescribed number of items of the judgment rule, a mail process including (a) blockage of delivery to the user and (b) transmitting a pseudo error message replicating an undelivery mail to the source is carried out.

Claims

1. An email processing method for selecting emails of a prescribed type undesirable to users and processing the selected emails, comprising the steps of:

receiving each email at a point on a path from a source of the email to a user and classifying and accumulating received emails based on prescribed information contained in the received emails; and

judging whether the emails accumulated in each of classified groups are emails of the prescribed type or not according to a prescribed algorithm.

2. The email processing method according to claim 1, wherein the prescribed information is information for specifying a group of emails having a high probability of having been transmitted by the same source.

3. The email processing method according to claim 2, wherein the information for specifying a group of emails having a high probability of having been transmitted by the same source is information on relaying of the emails.

4. The email processing method according to claim 3, wherein the information on relaying is information on relay paths of the emails, and the classification is made by the relay paths.

5. The email processing method according to claim 3, wherein the information on relaying is server names or domain names of relay devices on relay paths of the emails, and the classification is made by the server names or domain names.

6. The email processing method according to claim 1, wherein the judgment on whether emails of the prescribed type or not according to a prescribed algorithm includes ranking in regard to whether emails of the prescribed type or not.

7. The email processing method according to claim 6, further comprising the step of executing different processes to the emails of different classified groups, respectively, depending on the result of the ranking.

8. The email processing method according to claim 6, wherein the emails of each of the classified groups are ranked by the prescribed algorithm among three ranks:

emails of the prescribed type, emails that might be of the prescribed type, and normal emails.

9. The email processing method according to claim 6, wherein the number of ranks in the ranking is variable.

10. The email processing method according to claim 6, wherein the prescribed algorithm includes threshold values corresponding to the ranks to be used as criteria for ranking the emails of each of the classified groups, and the threshold values are variable.

11. The email processing method according to claim 1, wherein the prescribed algorithm is alterable.

12. The email processing method according to claim 1, wherein the prescribed algorithm includes judgment on whether or not the emails accumulated in each of the classified groups satisfy each item of a judgment rule containing at least one of the following items:

(1) the number of received emails per unit time is a first threshold or more, and

(2) the number of emails having an invalid destination address is a second threshold or more,

and judges whether the emails of each of the classified groups are emails of the prescribed type or not based on the result of the judgment.

13. The email processing method according to claim 1, wherein the prescribed algorithm includes judgment on whether or not the emails accumulated in each of the classified groups satisfy each item of a judgment rule containing at least one of the following items:

(1) the number of received emails per unit time is a first threshold or more,

(2) the number of emails having an invalid destination address is a second threshold or more,

(3) the source address is invalid,

(4) the degree of difference of the destination address between emails in the classified group is a third threshold or more,

(5) the mail text contains prescribed contents, and

(6) the mail text contains a prescribed URL,

and judges whether the emails of each of the classified groups are emails of the prescribed type or not based on the result of the judgment.

14. The email processing method according to claim 13, wherein the degree of difference of the destination address in the item (4) of the judgment rule is calculated based on Hamming distance between destination address codes.

15. The email processing method according to claim 1, further comprising the step of continuing the reception, classification and accumulation of the emails until an accumulation condition, specifying at least one of accumulation time and the number of accumulated emails, is satisfied.

16. The email processing method according to claim 1, further comprising the step of preventing transmission of information on each user at the destination of each email judged to be of the prescribed type to the source of the email of the prescribed type.

17. The email processing method according to claim 1, further comprising the step of executing a process including at least one of the following items for the emails judged to be of the prescribed type:

(a) blockage of delivery to the user,

(b) transmitting a pseudo error message, replicating an undelivery mail which is returned by a mail server to the source when undeliverable, to the source,

(c) deletion,

(d) blocking an undelivery mail from being returned to the source when the undelivery mail is transmitted by a prescribed mail server,

(e) transmitting a warning message to the source,

(f) preserving information on the emails of the classified group,

(g) inquiring of each user whether to deliver each email of the classified group or not and processing the email according to a reply of the user to the inquiry,

(h) rejection of domain name service regarding a prescribed mail server requested by a device corresponding to the source of the emails of the classified group, and

(i) rejection of requests for connection to a prescribed mail server made from the IP address of a device corresponding to the source of the emails of the classified group.

18. The email processing method according to claim 1, wherein the emails include undelivery mails each of which is transferred from a prescribed mail server to the source when an email to a user at the destination is undeliverable.

19. An email processing method, comprising the steps of:

receiving emails while classifying and accumulating the received emails based on information on a source and/or relaying of email contained in the received emails until an accumulation condition, specifying at least one of accumulation time and the number of accumulated emails is satisfied;

judging whether or not the emails accumulated in each of classified groups satisfy each item of a judgment rule containing at least one of;

(1) the number of received emails per unit time is a first threshold or more,

(2) the number of emails having an invalid destination address is a second threshold or more,

(3) the source address is invalid,

(4) the degree of difference of the destination address between emails in the classified group is a third threshold or more,

(5) the mail text contains prescribed contents, and

(6) the mail text contains a prescribed URL according to a judgment rule application condition specifying which items of the judgment rule should be applied;

judging whether or not each of the classified groups obeys a comprehensive judgment rule which employs the number of satisfied items in the items specified by the judgment rule application condition as its condition of judgment; and

executing a prescribed mail process including at least one of the following items for the emails of the classified groups judged to obey the comprehensive judgment rule;

(a) blockage of delivery to the user, and

(b) transmitting a pseudo error message, replicating an undelivery mail which is returned by a mail server to the source when undeliverable, to the source.

20. The email processing method according to claim 19, further comprising the steps of:

collecting statistics on the result of the judgment on the comprehensive judgment rule by executing the sequence of processes described in the email processing method at least once; and

setting or altering contents of at least one of the accumulation condition, the judgment rule, the judgment rule application condition and the comprehensive judgment rule depending on the collected statistics.

21. The email processing method according to claim 19, further comprising the step of receiving input for setting or altering contents of at least one of the accumulation condition, the judgment rule, the judgment rule application condition and the comprehensive judgment rule via a user interface.

22. The email processing method according to claim 19, wherein classified groups corresponding to a prescribed exceptional rule are excluded from the targets of the prescribed mail process even when the classified groups obey the comprehensive judgment rule.

23. The email processing method according to claim 22, wherein the prescribed exceptional rule includes at least one of the address of a source to be excepted, the domain name of a source to be excepted, a time slot in which the prescribed mail process is not executed, and a time period in which the prescribed mail process is not executed.

24. The email processing method according to claim 19, further comprising the steps of:

acquiring a delivery rejection condition, containing at least one of a domain name and a source address for rejecting email delivery, from a prescribed server when a user has registered the delivery rejection condition with the prescribed server; and

determining classified groups as the targets of the prescribed mail process based on the acquired delivery rejection condition.

25. The email processing method according to claim 19, wherein:

the number of satisfied items of the judgment rule in the items specified by the judgment rule application condition is defined in the comprehensive judgment rule as a factor for ranking, and

each of the classified groups is ranked according to the comprehensive judgment rule so that the rank will become higher as the number of satisfied items of the judgment rule gets larger, and

the prescribed mail process is executed at least for emails of a classified group that is ranked among the highest rank by the ranking.

26. The email processing method according to claim 25, wherein the accumulation condition is altered and the sequence of processes described in the email processing method is continued further for at least one classified group that is not ranked among the highest rank by the ranking.

27. A system for selecting emails of a prescribed type undesirable to users and processing the selected emails, comprising:

a mail classification system for receiving emails and classifying and accumulating the received emails based on prescribed information contained in the received emails;

a judgment system for judging whether the emails accumulated in each of classified groups are emails of the prescribed type or not according to a prescribed algorithm; and

an email processing system for executing a process based on the result of the judgment.

28. A server device for selecting emails of a prescribed type undesirable to users and processing the selected emails, comprising:

a mail classification unit for receiving emails and classifying and accumulating the received emails based on prescribed information contained in the received emails;

a judgment unit for judging whether the emails accumulated in each of classified groups are emails of the prescribed type or not according to a prescribed algorithm; and

an email processing unit for executing a process based on the result of the judgment.

29. A computer-readable record medium storing a program for instructing a computer to implement:

a classification function for receiving emails and classifying and accumulating the received emails based on prescribed information contained in the received emails;

a judgment function for judging whether the emails accumulated in each of classified groups are emails of the prescribed type or not according to a prescribed algorithm; and

an email processing function for executing a process based on the result of the judgment.