sendmail is a general-purpose internetwork mail routing facility under the UNIX® oper- ating system.
This document serves as the Installation and Operation Guide for Sendmail Version 8.747, a general-purpose internetwork mail routing facility designed for the UNIX operating system. It details the implementation of RFC standards for mail transport and headers, functioning as a crossbar switch to relay messages between domains while allowing for limited header editing.
Sendmail implements a mail routing facility under the UNIX operating system.
It can be configured to exceed these protocols in many cases, and those cases are described in the guide.
Sendmail reads the alias file into memory on every invocation, which can be slow.