Troubleshooting of mail failures caused by Postfix failures

The last day, I received a lot of feedback from users, reflecting that emails from several websites could not be received normally.

Initially, it was caused by the stress test of the mail system. after notifying the O & M personnel to perform system monitoring, it was found that tens of thousands of emails were blocked in the mail service queue.

After a detailed investigation, it was found that mailtoken, the built-in security software of Postfix, has expired and needs to be upgraded.

Emails in all queues are lost during the upgrade.

This reminds us that the email server should pay attention to the following issues:

1. The mail server is often a single point, and Server Load balancer needs to be considered;

2. Email Service exception alert;

3. backup and recovery of the mail queue.

My friend sery provides the Postfix email backup script, which can be viewed here: http://sery.blog.51cto.com/10037/45500.