Bug#377714: ITP: avenger -- highly configurable, MTA-independent SMTP filter server

["Robert S. Edmonds" <edmonds@debian.org>]

Package: wnpp
Severity: wishlist
Owner: "Robert S. Edmonds" <edmonds@debian.org>

* Package name    : avenger
  Version         : 0.7.6
  Upstream Author : David Mazieres
* URL             : http://www.mailavenger.org/
* License         : GPL, BSD
  Programming Lang: C, C++
  Description     : highly configurable, MTA-independent SMTP filter server
 Mail Avenger is a highly-configurable, MTA-independent SMTP (simple mail
 transport protocol) server. It allows you to reject spam during mail
 transactions, before spooling messages in your local mail queue. You can
 specify site-wide default policies for filtering mail, but individual users
 can also craft their own policies by creating avenger scripts in their home
 directories.
 .
 Compared to traditional (.forward, .qmail, etc.) spam filtering, filtering
 during an SMTP transaction gives you more options. For instance, you can
 reject mail with an SMTP error code, causing a bounce only if the client is
 a legitimate MTA, not if it is a spambot. You can temporarily defer mail,
 accepting the message later if the sender tries again from the same IP
 address--a technique known as greylisting. You can even embed
 cryptographically secure expiration times in temporary mail addresses to
 validate mail before receiving the message body.
 .
 Compared to traditional spam filtering, filtering during the SMTP
 transaction also gives you more information. Mail Avenger collects a wide
 array of information about SMTP connections from clients, including TCP SYN
 fingerprints (which often identify the client OS) and network route
 information. Mail Avenger also flags properties of client SMTP
 implementations, such as whether they use pipelining, issue illegal SMTP
 commands, or deviate from the protocol in other small ways. Scripts can
 easily track this information on a per-sender basis using a simple database
 utility (included in the distribution). Thus, anomalies can be flagged when
 known senders exhibit radically different client behavior. Much of the
 information collected is also recorded in a new mail header, X-Avenger:,
 which can be fed to Bayesian content filters to improve accuracy.
 .
 A partial list of features:
  * Mail-bomb protection
  * TCP filtering
  * Network-level traffic analysis
  * SMTP-level traffic analysis
  * SMTP callbacks
  * Per-user and per-user-extension mail scripts
  * Per-user mail relay checks
  * Virtual domain mapping
  * Alias to user mapping
  * RBL support
  * SPF
  * SPF language queries
  * Asynchronous DNS queries
  * "Bodytest" support
  * SMTP STARTTLS support
 .
 Mail Avenger is MTA-independent. It simply passes messages to a
 configurable sendmail program, and should therefore be compatible with any
 MTA that has a sendmail-like mail injection program. It has been tested
 with both sendmail and qmail, and others have reportedly used it with
 postfix.
 .
 Mail Avenger is free software. It runs on Linux, OpenBSD, FreeBSD, and
 MacOS X, and will likely run with little or no modification on other
 Unix-like operating systems. Please let us know if you experience any
 portability problems.