Google Message Security Troubleshooting Guide - Manual (Page 57)

Mail Flow Troubleshooting 59
The graph may instead look like this:
Here are the most common causes for no activity in the Delivery Manager graphs,
and the steps to resolve them:
• Routing Problems
There may be other routing problems. To find out more about what’s
happening, run the SMTP Message Test: “Test mail flow through the data
center.” For instructions, see SMTP Message Test.
• Incorrect MX records
If your MX records are set improperly for this domain, mail will never reach the
message security service.
Run the MX records test. For instructions, see MX Record Test.
If there is a problem with your MX records, switch your MX records so they
route mail to the message security service properly.
• Domain not added to the email security service
Check that your domain is registered. If you have changed your MX records
without adding your domain, this may cause problems. See Add a Domain for
Filtering.
Interpret Delivery Manager Graphs: Messages Blocked
If the delivery manager graph shows a red line, this indicates that messages are
being blocked. (The sidebar will also show no successful connections and many
failed connections.)