POPFile
Encyclopedia
POPFile is a free
, open source
, cross-platform mail filter originally written in Perl
by John Graham-Cumming
and maintained by a team of volunteers. It uses a naive Bayes classifier
to filter mail. This allows the filter to "learn" and classify mail according to the user's preferences. Typically it is used to filter spam mail. It can also be used to sort mail into other user defined "buckets" or categories - for example, the user may define a bucket into which work email is sorted.
The program works in several different modes. In the most popular mode, it sets itself up as a proxy
between the email client and the POP3 server. As mail is downloaded via POP3, the filter identifies and classifies mail and makes a user defined modification to the subject line, appending the name of the appropriate bucket. The user then sets up rules in the mail client to sort the mail based on the subject line modification. An HTML
based interface can be used to instruct POPFile, allowing users to correct errors in classifications and thus train the system to be sensitive to the user's specific requirements.
As an alternative to the subject-line modification (or as a supplement to it), the system can also be configured to use custom mail headers instead.
In another possible mode, POPFile can work as an IMAP client that monitors an IMAP server for incoming mail and also for messages moved by the user. Incoming emails are categorized and then immediately moved to the folder corresponding to the categorization. To train POPFile in this mode, the user only needs to move the message to the correct folder, i.e. to the folder where POPFile should have moved the message.
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
, open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
, cross-platform mail filter originally written in Perl
Perl
Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...
by John Graham-Cumming
John Graham-Cumming
John Graham-Cumming is a British programmer best known for having originated a successful petition to the British Government asking for an apology for its persecution of Alan Turing for his homosexuality....
and maintained by a team of volunteers. It uses a naive Bayes classifier
Naive Bayes classifier
A naive Bayes classifier is a simple probabilistic classifier based on applying Bayes' theorem with strong independence assumptions...
to filter mail. This allows the filter to "learn" and classify mail according to the user's preferences. Typically it is used to filter spam mail. It can also be used to sort mail into other user defined "buckets" or categories - for example, the user may define a bucket into which work email is sorted.
The program works in several different modes. In the most popular mode, it sets itself up as a proxy
Proxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
between the email client and the POP3 server. As mail is downloaded via POP3, the filter identifies and classifies mail and makes a user defined modification to the subject line, appending the name of the appropriate bucket. The user then sets up rules in the mail client to sort the mail based on the subject line modification. An HTML
HTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
based interface can be used to instruct POPFile, allowing users to correct errors in classifications and thus train the system to be sensitive to the user's specific requirements.
As an alternative to the subject-line modification (or as a supplement to it), the system can also be configured to use custom mail headers instead.
In another possible mode, POPFile can work as an IMAP client that monitors an IMAP server for incoming mail and also for messages moved by the user. Incoming emails are categorized and then immediately moved to the folder corresponding to the categorization. To train POPFile in this mode, the user only needs to move the message to the correct folder, i.e. to the folder where POPFile should have moved the message.