You can troubleshoot delivery problems for messages using Email Log Search (ELS).

Before you start, make sure the person who's missing messages completes these recommended steps.

Step 1: Confirm Delivery

• From a Google Workspace user to a non-Google email provider—Confirm that the message appears in ELS, which means it was sent successfully. Then, check with the receiving domain for any network or email delivery issues. If the message doesn't appear in ELS, trace the message starting with the sender. 

• From one Google Workspace user to another—Confirm that the message appears in ELS. If the message doesn't appear in ELS, verify the MX records of the recipient domain.

• From a non-Google email provider to a Google Workspace user—Search for the message with ELS. If the message doesn't appear in ELS, contact the sender. Ask them to review their email filters and firewall settings.

Step 2: Confirm post-delivery message status

If you confirmed that a recipient in your domain got the message, check the message Post-delivery message status to help you find the message in the user’s mailbox. 

Older than 30 days: If the message was received more than 30 days ago, message delivery logs won’t be available. By selecting this date range, you can search with a message ID and the recipient details to view the status of the message in a user’s mailbox.

Step 3: Evaluate Email Log Search results

Consider these tips when evaluating ELS results:

• If a message known to exist and sent to a registered user doesn't appear in ELS, it's likely that the message never made it to the Google network. Check the route leading to Google to identify the problem. Contact the sending or recipient domain to help troubleshoot the issue.

• If a delayed message shows a Google transit time of less than 10 minutes, a third-party provider may be the cause of the delay. Use the message header analyzer to examine the route a message took, and determine where the message was delayed.

• Messages bounced with "The email account that you tried to reach does not exist" won't show in ELS unless you forward the message to a catch-all or legacy server.