This guide is a companion to the Postfix, Dovecot, and MySQL installation guide. Because setting up a mail server is tricky, we’ve created this companion troubleshooting guide to help you work through and resolve any problems you might be experiencing. By the time you reach the end of this guide, you’ll know how to debug problems with your Postfix, Dovecot, and MySQL mail server.
The first section, Troubleshooting Checklist_, has a top-down approach to troubleshooting that will help you find specific errors for your mail server. The second section, Step-by-Step Configuration_, uses a bottom-up approach that shows you how to get a basic mail server functioning and then gradually add more features.