Simple definition
Message Trace in Exchange Online helps administrators track the processing and delivery status of email messages.
Technical definition
A message trace shows transport events and available delivery information, including sender, recipient, timestamps and processing outcomes. Availability and detail depend on Microsoft 365 reporting features and retention limits.
What is Message Trace used for?
Investigate messages that are delayed, rejected, quarantined or not received.
Practical example
An administrator searches by recipient and time range to determine whether Exchange Online received and delivered a message or applied a filtering action.
Common problems
- Research on bad time
- Address not taken into account
- Confusion between transport and user box
Related terms
To be noted: precise behaviors and commands may vary depending on the versions, products and architectures.