SpamAssassin Flagging Milter is a Sendmail milter daemon for Unix systems. It sends email to Spamassassin and then modifies the headers based on the results provided by Spamassassin. It adds a Spam or NonSpam entry in the headers, which client programs can then use to help filter junk. This program is based on another program, milter-spamd: http://www.benzedrine.cx/milter-spamd.html.
Dkfilter is a DomainKeys implementation for the Postfix mail transfer agent. It is implemented as two filters (or SMTP proxies). There is an "outbound" filter for adding DomainKeys signatures to outgoing email and an "inbound" filter for verifying signatures of incoming email. The filters can be plugged into Postfix as either Before-Queue or After-Queue Postfix content filters. For more information about DomainKeys, see http://antispam.yahoo.com/domainkeys.
contraccions validates word contractions in the Catalan language. Word contractions in Catalan spelling are very complex and the function enclosed in this package allows a spellchecker to warn about wrong expressions and to suggest something to correct them. It returns a code to indicate the type of the error and the location of the error in the expression, and allows a spellchecker to perform incremental validation.
PigeonDeliver is the delivery agent of the PigeonAir project, a solution to easily build up clustered, scalable, and modular email services. PigeonDeliver is modular in nature, allowing it to be used on Postfix and other MTAs using their own native APIs without performance loss. It allows mail services to be easily and transparently distributed among a cluster of mail server, easily supporting new services and new modules added using the PigeonDeliver API, which simplifies writing filters and/or delivery agents.
dkimproxy is an SMTP proxy that signs and/or verifies Domain Keys Identified Mail (DKIM). It is designed to work with Postfix. It comprises two separate proxies: an "outbound" proxy for signing outgoing email, and an "inbound" proxy for verifying signatures of incoming email. With Postfix, the proxies can operate as either Before-Queue or After-Queue content filters.