Office 365 admins, do you find yourself needing to troubleshoot email delivery problems? The Exchange Online message trace tool allows you to track specific messages sent in the last 90 days.

Let’s say one of your users logs a help desk ticket. He’s frustrated because he’s sent several emails to an external recipient, but the external recipient let him know that the emails never came. You’ll use message trace to determine if the emails your user sent were actually delivered.

1. From the main admin center, choose the Exchange admin center from the left pane.
2. Under mail flow, select message trace.
3. Alter the options of your message trace for your scenario.
4. Click OK.

You can then examine the output of the mail trace for issues.