DKIM-Verify is a software application that can provide DKIM verification for non-DKIM-aware MDAs. Using DKIM-Verify, which functions as a "wrapper" for the MDA, mail originating from and destined for the local domain can be verified. In addition, DKIM-Verify can integrate with mailing list software to provide verification of messages received for later distribution.
Masqmail is an MTA (mail transport agent) for notebooks, workstations, home servers, and generally any host with no permanent network connection. It has special support for multiple transfer routes (e.g. to different mail providers). Address rewriting can be done in several ways. It is a slim replacement for full-blown MTAs such as sendmail, exim, qmail, or postfix and for the intended uses, configuration is much simpler.
Built upon Maarch Framework, Maarch LetterBox is a complete mail management solution. It is developed exclusively by its user base. It handles incoming, outgoing, and internal mail. It ships with an inline editor to generate mail or answers from templates. It sends alerts and notifications on new mail, late mail, etc. It manages mail circulation between users through virtual mail baskets. It logs every action on documents and on the configuration of the application. It offers tools to monitor mail activity.
DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP exchange gateway allowing users to use any email/calendar client (e.g. Thunderbird with Lightning or Apple iCal) with an Exchange server, even from the Internet or behind a firewall through Outlook Web Access. DavMail now includes an LDAP gateway to Exchange global address book and user personal contacts to allow recipient address completion in the mail compose window, and full calendar support with attendees free/busy display.
Scandalo is a very efficient and fast mail frontend for the clamdscan virus scanner. In other words, it is a simple mail filter that works as a wrapper for clamd, the famous Clamav antivirus daemon. Once integrated in maildrop or any MTA or MUA, it can quickly read messages and send them to the clamd process for virus scanning using the clamdscan utility. When a virus is found, the message is marked with a header, so you can easily set up your mail filter or MUA to drop, quarantine, or move the infected message to a mail folder.