Book Image

Qmail Quickstarter: Install, Set Up and Run your own Email Server

Book Image

Qmail Quickstarter: Install, Set Up and Run your own Email Server

Overview of this book

This book starts with setting up a qmail server and takes you through virtualization, filtering, and other advanced features like hosting multiple domains, mailing lists, and SSL Encryption. Finally, it discusses the log files and how to make qmail work faster. Qmail is a secure, reliable, efficient, simple message transfer agent. It is designed for typical Internet-connected UNIX hosts. Qmail is the second most common SMTP server on the Internet, and has by far the fastest growth of any SMTP server. Qmail's straight-paper-path philosophy guarantees that a message, once accepted into the system, will never be lost. Qmail also optionally supports maildir, a new, super-reliable user mailbox format.
Table of Contents (13 chapters)

The Log Files


When analyzing qmail's operation for almost any purpose, the first place to begin looking is in qmail's log files. In a standard qmail setup, there are two sources of log files: one for qmail-send and one for qmail-smtpd. By default, these contain both useful information for tracking down individual messages and useful information for analyzing qmail's performance.

The log output of both qmail-send and qmail-smtpd is organized in a simple way, though it can easily become confusing.

The Basic qmail-smtpd Log

The qmail-smtpd log file is the simpler of the two because qmail-smtpd does not generate log output. The qmail-smtpd log records the output of tcpserver. tcpserver generates five log entries for every connection:

  1. 1. When the connection opens, it logs the current number of connections and the maximum number of connections.

  2. 2. When the connection opens, it logs the client and the process-identifier (PID) of the child process handling that connection.

  3. 3. After all the necessary...