SMG “Sender Aborted Connection” Errors Caused by Active Directory Connectivity Issues

Products

• Messaging Gateway

Issue/Introduction

When reviewing Message Audit Logs on Symantec Messaging Gateway (SMG), you may observe a high number of messages with the verdict “sender aborted connection.” Further investigation of the mail logs often reveals errors related to recipient address resolution failures.

failed to fetch recipient
com.symantec.sms.dds.api.exception.DataAccessUnavailableException: The data source is unavailable

Cause

This indicates that SMG is unable to connect to Active Directory to validate recipient addresses.

When Recipient Validation is enabled, SMG must be able to:

• Resolve the Active Directory hostname (DNS resolution)

• Establish a network connection to Active Directory

• Query Active Directory to verify recipient addresses

Resolution

1. Temporarily disable address resolution for local domains in Protocols > Domains to restore mail flow while the directory issue is investigated.
2. Confirm that Messaging Gateway scanners can resolve the hostname of all configured directory servers in Administration > Directory Integration
3. Confirm that Messaging Gateway scanners can connect to the configured Address Resolution data source via telnet from the admin command line
4. Confirm that credentials for the directory data source are correct by running a test query from Administration > Directory Integration

Once connectivity and operation of the Recipient Validation data source is confirmed, Address Resolution may be re-enabled for local domains in Protocols > Domains.