Messages in the Symantec Messaging Gateway (SMG) delivery queue are not delivered to their intended mail server.
Messages can accumulate in the delivery queue when the SMG Mail Transfer Agent (MTA) is unable to successfully deliver messages to their intended destination.
Messages can accumulate in the delivery queue for a number of reasons, including the following:
In general, when delivering mail from Messaging Gateway, there may be some undeliverable messages in the delivery queue. Some messages may not be properly addressed, or the destination mail server is not accessible.
View the delivery queue at Status > Message Queues > Queue: Delivery, which provides more detailed information as to why messages have been queued. Look under the "Error" column of the queue listing.
For more information, search the Symantec Knowledge Base for the specific status message or SMTP code.