getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
cats2procmailrc is a filter to generate a .procmailrc file from a much terser and friendlier file consisting mostly of single-line rules. These suffice to do the most common mail filing, making maintenance of a procmailrc very easy for someone with more than a few filing rules. Each rule normally names the folder, an optional subject tag, and the pattern. Raw procmail rules may also be included for those rare complex filings.
The milter module for Python provides a python interface to Sendmail's libmilter that exploits all its features. Milters can run on the same machine as sendmail, or another machine. The milter can even run with a different operating system or processor than sendmail. Sendmail talks to the milter via a local or internet socket, and keeps the milter informed of events as it processes a mail connection. At any point, the milter can cut the conversation short by telling sendmail to ACCEPT, REJECT, or DISCARD the message. After receiving a complete message from sendmail, the milter can again REJECT or DISCARD it, but it can also ACCEPT it with changes to the headers or body.
Roap is a text file processor. It scans a text file, extracts regions that match specified patterns, and processes these regions sequentially using specifed executables. Each executable reads the region as stdin, and their combined stdouts are written as the stdout of Roap. Patterns and executables are specified using XML.
Active Spam Killer (ASK) protects your email account against spam by confirming the sender's email address before actual delivery takes place. The confirmation happens by means of a "confirmation message" that is automatically sent to all "unknown" users. Once the sender replies to that message (a simple reply will do), future emails from that person will be delivered immediately. You can also specify (regexp) addresses to be immediately accepted, rejected (with a nastygram) or ignored. The package also includes a utility to scan your old mailboxes and generate a list of emails to be accepted automatically.
Sedsed is a Python script that masters sed scripts. It generates sed debug files in sed, which lets you debug scripts with your own version of sed (Linux, DOS, etc.). It's also a script beautifier, doing indentation and spaces/comments formatting. It can also convert sed scripts to colorful HTML files.