Blacklist Documentation

Blacklists may be on a per-user (user@domain.com) basis, or a per-domain (domain.com) basis. A user's personal blacklist is first checked, followed by the associated domain blacklist. If it is caught by one of the blacklists, the message is rejected. A blacklist entry can be one of four things:

Email Address: This is the envelope sender address, in the form "user@domain.com". Note that this is _not_ necessarily the same as the From: header!
Hostname: This is a hostname or domain name of the sending server. For example, "my.host.domain.com", or "domain.com", or even just "com". This will check all subdomains of a given hostname for a match in the blacklist. Unlike whitelists, a hostname entry in a blacklist will also match against the domain of the envelope sender address.
IP Address: This is an IP address of the sending server. For example, "10.1.2.3". It may also be a pseudo-classful netblock in the form "10.1.2", "10.1", or even just "10", or it may be a CIDR address in the form "10.1.2.0/25".
RegEx: This is a [POSIX] regular expression in the form "/pattern/". RegEx entries are matched against the envelope sender address or the sending server's hostname.

A comment can be appended to a blacklist entry in the web interface by entering "// (comment)" after the entry. For example: "10.0.0 //I don't like this network"