spamdyke For Linux

spamdyke is an open source software written in C as a drop-in filter for the qmail application, replacement for sendmail, designed to provide numerous features, including graylisting, connection-time blacklisting, DNS RHSBL/RBL checking, improved logging, and sender MX checking.

spamdyke has been engineered in such a way that it provides TLS and SMTP AUTH to unpatched qmail servers. It can be used to monitor and intercept SMTP connections between a qmail server and a remote host.

The filter is capable of blocking spam while the spammer is still connected, without requiring any additional storage or processing. spamdyke features numerous anti-spam filters, as well as various features that will enhance qmail.

spamdyke includes a wide variety of anti-spam filters, organized in four main categories, such as reverse DNS filters, whitelist and blacklist filters, graylist filters and other filters that can be viewed at a glance in the next section.

Among the reverse DNS filters, we can mention support for requiring reverse DNS names, support for requiring reverse DNS names to resolve with IP addresses, support for requiring reverse DNS names to be real instead of dynamically assigned, as well as support for requiring a valid MX (Mail Exchanger) for sender's domain name.

Whitelist/blacklist filters include the ability to search local IP addresses and reverse DNS whitelist or blacklist files, search DNS RBLs (real-time whitelists and blacklists), search DNS RHSBLs (righthand-side whitelists and blacklists), search recipient and sender whitelist or blacklist files, as well as to search message headers for certain content.

On the other hand, the graylist filters will allow you to greylist certain recipient domains, to greylist connections from certain reverse DNS domains or IP addresses, to skip greylisting for certain domains, reverse DNS domains or IP addresses, and to implement maximum and minimum ages for greylist entries.