email2sms is a filter written in Perl which converts an e-mail into a form suitable for sending as an SMS message. Its main advantage over the alternatives is that it uses the CPAN module Lingua::EN::Squeeze to compress the text down to as little as 40% of its original size, so you can get much more of your e-mail into the 160 character limit imposed by SMS. It is fully MIME compatible, and has many configurable options, including removal of quoted text. Ideal for use with procmail. A Perl script for sending the output to a typical e-mail to SMS web gateway is included.
fmscore is a Perl5 program which uses the Mail::Freshmeat Perl module to parse freshmeat daily e-mail newsletters, and then rank them by interest according to highly flexible user-supplied ranking rules. Articles below a specified score will be removed from the output. fmscore is intended/suitable for use as a procmail filter.
MailWatch is a program for analyzing mail traffic. As each message is received, Mailwatch records summary information about it. Later, it can generate a textual report, showing the number of posts during a time period, who the most prolific posters were, and what the most popular topics were. It is targeted at the end user who wishes to generate statistics for personal email or mailing lists.
parp is a powerful, extensible e-mail filter with sophisticated anti-spam capabilities. It's designed as a complete replacement for procmail, is MIME-aware, and acts as a filter, daemon, or on mailboxes. It uses the Open Relay Database as part of its spam-detection heuristics, and it has a DBM-format database of trusted e-mail addresses to ensure that false positives are kept to a minimum. It can perform duplicate removal by message ID, and has many other features.
The procmail and formail mail processing package can be used to create mail-servers, mailing lists, sort your incoming mail into separate folders/files (real convenient when subscribing to one or more mailing lists or for prioritising your mail), preprocess your mail, start any programs upon mail arrival (e.g. to generate different chimes on your workstation for different types of mail) or selectively forward certain incoming mail automatically to someone.
Text::Template is a module for doing dynamic content generation in Perl. You can embed any Perl code into a file, and then make a call to the module to `fill in' the blanks in the file. This is good for generating HTML pages and form letters. It was first released in 1995 and is very stable, very fast, and very reliable. It is also integrated with Perl's Safe module in case you don't trust the template author.
Vipul's Razor is a distributed, collaborative, spam detection and filtering network that exploits the broadcast characteristic of spam distribution to limit its propagation. The primary focus of the system is to identify and disable an email spam before its injection and processing is complete. Razor establishes a distributed and constantly updating catalogue of spam in propagation. This catalogue is used by clients to filter out known spam.