Distribution List Expansion mechanism in SMG

Products

• Messaging Gateway

Issue/Introduction

When Distribution List (DL) Expansion is enabled in Symantec Messaging Gateway (SMG), inbound messages addressed to a distribution list are modified at the SMG level. SMG queries the Directory Data Source (Active Directory/LDAP), expands the group membership, and splits the email into individual message envelopes for each member before transferring the mail to the downstream server.

 

Resolution

If the organization's goal is to hide or mask the individual email addresses belonging to a distribution list within the gateway, this configuration will bypass that requirement.

• The Mechanism: Because SMG expands the list locally, the Message Audit Logs (MAL) and delivery attempts will explicitly show separate, distinct transactions directed to each individual member's email address, rather than a single transaction to the DL address.