Issue:
Emails are blocked by the Messaging Security Gateway (MSG) or Protection Service for Email (PSE) maxsize firewall rule despite being seemingly smaller than the limit.
Resolution:
The maxsize firewall rule may include multiple criteria. Most likely one of the other criteria are being met by the message. Here is an example of the maxsize firewall rule criteria:
Message size greater than 52428800 Bytes
OR Attachment count greater than 256
OR Total Uncompressed Attachment size greater than 52428800 Bytes
OR File count in archive greater than 256
OR File depth in archive greater than 20
To check and modify the rule used in your appliance:
- Log in to the MSG Web UI
- Select the Email Protection-tab
- Navigate to Email Firewall -> Rules using the left-side menu
- Locate the rule called maxsize from the list of rules
- The settings of the rule can be checked directly from the list
- To modify the rule, click on Edit Rule, make the necessary changes and click Save changes
Article no: 000001618