Mail rejected when not including a top-level domain in the sender information

Products

• Messaging Gateway

Issue/Introduction

A server sending mail to your domain is getting the messages rejected.  The bounce back being sent includes the error message "554: Domains without a subdomain are not allowed."

554: Domains without a subdomain are not allowed.

Cause

This is caused when the sender system does not include a top-level domain in the 'mail from' line of the smtp transmission. This information is required by Symantec  Brightmail  Gateway antispam in order to process the message.

Resolution

Inform the sender that the top-level domain data must be given when transmitting a SMTP message through Symantec Brightmail  Gateway antispam.