inline_smtp 0.95

The inline_smtp perl script was created to allow filtering of incoming mail on a separate server that houses the mailspools without running a full blown MTA. While its possible to configure another MTA, e.g. postfix, to relay all mail to a smart host and do filtering through postfix, the queue can get behind easily, and on a busy host thousands of messages can get queued in a few hours causing delays in delivery from a few minutes to several hours. Because its filtering while redirecting, mail arrives as fast as if it were coming directly to the final mail server because its relayed as the message is received.

inline_smtp works by accepting connections and relaying the conversation to the maildrop host as it takes place, so any 550 messages pass through instantly instead of getting the 550 on the relay server then having to process a bounce, which also fills the queue. inline_smtp understands enough of the smtp protocol to filter on rctp to: addresses and to process the mail body, optionally running it through a filter.