Message Trace in Microsoft 365

Source: Dev.to

Message Trace in Microsoft 365 is a valuable tool for investigating email delivery issues, tracking message flow, and ensuring that important emails reach their intended recipients. It provides a detailed record of the path an email takes through your organization’s email infrastructure, from the time it is sent until it is delivered to the recipient’s inbox.

Step 1: Access the Exchange Admin Center

Go to the Exchange Admin Center: .

Step 2: Starting a Message Trace

In the left navigation, select Mail Flow → Message Trace, then click Start a Trace.

Step 3: Message Trace Filtering Options

• Default – traces all messages.
• Filters – narrow the trace by sender, recipient, date range, delivery status, message ID, direction (inbound/outbound), or client IP.
• Output – choose to view the report online or download it as a CSV file.

Can’t Find a Message in Message Trace?

If a message does not appear in Microsoft 365 Message Trace, consider the following reasons:

• Message hasn’t reached Microsoft 365 – delays in routing or transit may keep the message out of the trace.
• Search criteria – ensure the sender, recipient, date range, and other filters are correct.
• Retention policy – older messages may have been deleted according to your organization’s retention settings.
• Hybrid deployments – Message Trace only covers Exchange Online. On‑premises email flows must be checked via on‑premises message tracking logs.

Message Trace is an essential tool for any IT administrator responsible for managing email infrastructure.