mysqmail-postfix-logger is a (very small) daemon that logs all SMTP traffic to an SQL database. It splits the information by domain and user for the From and To fields, making it very easy to count all the SMTP traffic for a given domain name. DTC (Domain Technologie Control) uses it for logging the SMTP traffic.
Postoffice is a simple SMTP mail server and client written with spam blocking in mind. It provides a greylist to slow down the rate of incoming spam, and can be configured to do antivirus checking on incoming mail either via the sendmail milter protocol or a traditional hard-coded AV program. Postoffice can be configured to deliver mail to accounts inside vm-pop3d-style virtual domains, and it can further be enabled to support AUTH LOGIN for people inside virtual domains, so they can use postoffice as a mail forwarder when replying to mail. Postoffice accepts (and ignores) many of the same command line options that are passed to sendmail, and it comes with the usual crop of sendmail compatable aliases; runq, mailq, newaliases, and sendmail.
libsrs2 is the next generation SRS library. SPF verifies that the Sender address of an email message matches (according to some policy) the client IP address that submitted it. When a message is forwarded, the sender address must be rewritten to comply with SPF policy. The Sender Rewriting Scheme, or SRS, provides a standard for this rewriting that is not vulnerable to attacks by spammers, is easy to parse by common mail filters, and handles multiple hops neatly and safely.
AfterLogic XMail Server is an email server. It supports ESMTP, TLS/SSL secure connections, SMTP authentication, account and domain aliasing, anti-spam features (IP-based and email address based), mailing lists, logging, remote administration, the Finger protocol, filters, and custom mail processing. AfterLogic XMail Server is based on the XMail server, but features simultaneous multi-user access to a POP3 mailbox, the ability to configure port numbers via a configuration file, a Windows installer, and a Web administration tool with an AJAX interface.
POPauthd is a Perl-based daemon that uses POP to authorize connecting hosts for SMTP relaying. It is particularly useful to authenticate roaming users with IP addresses that change often. The daemon runs in the background, watching the syslog for successful POP logins. When it sees one it enters the IP in sendmail's access database, giving the host authorization to relay through the server. The entries can be expired after a prescribed, configurable period of time with a companion script run via crontab.
AXIGEN is a fast, reliable and secure mail server with an open architecture. It is designed for easy management and allows full control of the email traffic from a central Web/CLI admin module. AXIGEN provides ESMTP, IMAP, and POP3 services and has been tested with standard mail clients. A special Webmail module enables email access and delivery from Web browsers. During the evaluation period, users are provided with full technical support.
Insight Server is a Linux-based email server utilizing open source components to provide a highly reliable, scalable, and cost effective email solution for customers of all sizes. It's designed to facilitate complete messaging and collaboration capabilities within a company. It supports all standard protocols, and provides backup and recovery tools, server redundancy, migration tools, and resource management.
The Gordano Messaging Suite (GMS) is a highly flexible and reliable suite of messaging products. Customers can choose which components meet their needs from email, Webmail, collaboration, instant messaging, calendaring, SMS, and list server software all of which can be complimented by high level anti-spam, anti-virus, and archiving options.