About tracking message transmission problems

To determine how many messages were not delivered due to problems during mailing execution, compare the total number of undelivered messages to the number of bounced messages. The difference is the number of messages that failed during mailing execution. For example, a message could fail during execution because it was rejected by the SMTP transmission server or conditional text criteria could not be met.

See the Mailing Execution History report report for more information about message failure during execution.

For more details about bounced messages, Deliver provides the Detailed Bounce report.