MailFront

SMTP Front Ends


Overview

The code for SMTP is divided internally into two sections: front-end and back-end code. The front-end code handles the low-level details of the protocol. The back-end code handles the validation and delivery details in a protocol-independant fashion.

Features

The following features are common to all SMTP front-ends:

Back Ends

smtpfront-echo

Uses the echo backend to simply echo back the sender and recipient parameters, and the size of the data to the client.

smtpfront-qmail

Uses the qmail validation features to validate addresses, and the qmail backend to deliver messages.

smtpfront-reject

If $SMTPREJECT is set, all SMTP commands are rejected with this message. If the message starts with a "-", a permanent error number is used and the leading "-" is stripped. If $SMTPREJECT is not set, it execs its command line.