Software

milter-abook
Documentation | LibSnert | Free Download
Part utility, part filter. This milter collects the recipient addresses of messages sent from white listed outbound senders. It can then optionally tag, reject, or discard mail from unknown inbound senders, which haven’t been white listed or previously cached.

milter-ahead
Documentation | LibSnert | Free Download
A “call-forward” milter that is intended for mail gateways to verify that mail recipients exist on an authoritative mail store before the gateway accepts the message. Think of it as a poor man’s LDAP. Many mail systems split the functions of mail transfer and that of storage & retrieval over two or more systems. Typically a mail gateway will blindly accept and forward mail to their mail store, but spammers often send mail to a domain using a dictionary of user names, resulting in many error messages that can sometimes saturate the mail gateway. This situation is often compounded by the mail gateway queuing those useless error messages for days as they attempt to send them back to the spammers that used throw away domains or mail servers that are now “off”, eventually resulting in hundreds of “double-bounce” errors being sent to the postmaster’s mailbox.
milter-bcc
Documentation | LibSnert | Free Download
This is a utility milter that can add to the recipient list of any inbound and/or outbound message one or more blind-carbon-copy (Bcc) recipients depending on the MAIL FROM: and/or RCPT TO: addresses for any given message. This is particularly useful for mail hosts that manage several domains that desire a simple and flexible way to send a copy of messages to one or more mail boxes without the need for aliases, .forward files, or similar.
milter-clamc
Documentation | LibSnert | Free Download
This milter provides an interface to the popular open source Clam Anti-Virus scanner.

milter-cli
Documentation | LibSnert | Free Download
This milter provides a means by which client connection and envelope details and/or message headers and content can be filtered using shell commands or scripts. Intended as a way to implement quick & dirty content filtering solutions when there is no other suitable milter available.

milter-gris
Documentation | LibSnert | Free Download
Grey-listing is a technique that uses the behaviour of a standard-compliant mail server to temporarily delay the acceptance of mail. When a sending mail server initially contacts a mail exchange to deliver a message, the details of the message are recorded and the mail exchange signals the sending mail server that the message is temporarily rejected. A normal mail server will place temporarily rejected messages into a retry queue and after an appropriate delay attempt to resend the message. The mail server accepts the message later, when the sender retries. The underlying principal here is that spammers use “mail cannons” to send as much mail as fast as they can and so will not implement retry queues

milter-length
Documentation | LibSnert | Free Download
A utility milter that can reject mail according to different message size limits per IP, domain name, or sender address.

milter-limit
Documentation | LibSnert | Free Download
Message limits are a means to control the number of messages that traverse a mail server according to domain, sender, or recipient. It could be used on the outbound side like Hotmail’s daily message limits to limit local user’s consumption (particularly if they appear to be infected by a mass mailing worm); it could be used inbound as an alternative to grey-listing. It could be enabled and disabled as needed during periods of peak mail activity such as during a virus outbreak or spam holiday season.

milter-link
Documentation | LibSnert | Free Download
Extracts URLs from a mail message and checks it against one or more URI blacklists. Can also verify if any link is bad or broken.
milter-ns
Documentation | LibSnert | Free Download
A utility milter that adds a report header to each message containing the sender’s NS records, suitable for downstream processing.

milter-spamc
Documentation | LibSnert | Free Download
This milter provides an interface to the popular open source SpamAssassin mail analysis tool, which returns a score based on a comprehensive set patterns and Bayesian checks.

milter-spiff
Documentation | LibSnert | Free Download
This is an independent implementation of the RFC 4408 Sender Policy Framework (SPF-Classic). This mail filter will accept, tag, reject, and/or discard email according to a domain’s published SPF records, which document the valid sources of mail for the domain.

Roundhouse
Documentation | LibSnert | Free Download
This is an SMTP multiplexer, which takes the input from an SMTP client connection and copies it to one or more SMTP servers. Intended as means to debug and test different mail server configurations using a production mail server’s live data stream.

Private Wimp MLM
Documentation | LibSnert | Free Download
A simple light weight mailing list manager. Works with Sendmail, PostFix, Exim, any MTA that supports piping a message through a program.