Scenario
You are using Exclaimer, and start to receive bounce-backs from sent messages, with a similar non-delivery report:
ERROR: 554 5.6.0 Message exceeded 50 hops, this may indicate a mail loop. Learn more at https://support.google.com/mail/?p=MailLoop 24sm247046edt.21 - gsmtp [Response from smtp-relay.gmail.com]
Reason
This issue is caused by messages looping between Exclaimer and G Suite, when routing via the Content Compliance rule and our server, usually because of header conditions not matching.
Resolution
To resolve this issue, you need to correct the header conditions of the Content Compliance rule.
To complete the steps described below, you will need:
G Suite Super Admin credentials
G Suite Super Admin credentials
To correct the header conditions:
- Login to the G Suite Admin Portal.
- Navigate to Apps > G Suite > GMail.
- Click on Advanced Settings.
- Locate your Content Compliance rule, by default this will be called Route to Exclaimer.
- Click Edit.
- Edit the Rule to match the below:
- Ensure that the Content field contains:
Not Contains Text X-ExclaimerHostedSignatures-MessageProcessed
- Click Save.
- Click SAVE at the bottom of the page: