Non-delivery details report in the new Exchange admin center in Exchange Online

The Non-delivery details report in the new Exchange admin center (new EAC) shows the most-encountered error codes in non-delivery reports (also known as NDRs or bounce messages) for users in your organization. This report shows the details of NDRs so you can troubleshoot email delivery problems.


By default, the report shows data for the last 7 days. If the report is empty, try changing the date range.

For permissions that are required to use this report, see Permissions required to view mail flow reports.

Overview of the Non-delivery details report.

The chart in the overview section contains the most-encountered NDR error codes for a given day. If you hover over a specific color in the chart, you'll see the number of messages for that specific error code.

The Non-delivery details section shows the following information for each date-error code combination:

  • Date
  • Count
  • Error code
  • Sample messages: This field contains the internet message IDs (also known as the Client IDs) of a sample of the original messages. This value is stored in the Message-ID header field in the message header and is constant for the lifetime of the message.

To quickly filter the results, click Search Search icon. and start typing a value.

To filter the results by date range or error code, use the boxes. You can specify a date range up to 90 days.

For more advanced filters that you can also save and use later, click Filter Filter icon. and select New filter. In the Custom filter flyout that appears, enter the following information:

  • Name your filter: Enter a unique name.

  • Click Add new clause. A clause contains the following elements that you need to enter:

    • Field: Select Date, Count, Error code or Sample messages.

    • Operator: Select starts with or is.

    • Value: Enter the value you want to search for.

    You can click Add new clause as many times as you need. Multiple clauses use AND logic (<Clause1> AND <Clause2>...).

    To remove a clause, click Remove Remove icon.

    When you're finished, click Save. The new filter is automatically loaded, and the results are changed based on the filter. This is the same result as clicking Filter and selecting the customer filter from the list.

    To unload a existing filter (return to the default list), click Filter Active filter icon. and select Clear all filters.

Click Export to export the displayed results to a .csv file.

See also

For more information about other mail flow reports, see Mail flow reports in the new EAC.