RegEx Documentation

There is currently one system-only filter in place which supports regular expressions (RegEx, RE). This is the spamtrap database (not to be confused with the spamtrap blacklist), and it is not user-accessible. This filter allows the Systems Administrator a level of control separate from the users for automation and protection of the mail server. It should be used cautiously and thoughtfully. The RegEx functions used are the POSIX functions in "regex.h".