Notification message logging

MTA message transaction log entriesshowing an empty envelope From address are the indication of a notification message, whether generated  externally and merely passing through the MTA, or whether generated by  the MTA itself.

For notification messages generated by the MTA itself, note that notification messages are generated through the  process channel. Indeed, typically the generation of notification messages is the sole function of the process channel. So MTA message transaction log entries showing a message being enqueued to the process channel typically  correspond exactly to the generation of a new notification message.

If the MTA option   is enabled, then when the MTA  generates a notification message it will include both the original  message-id and the message-id of the new, notification message in the  message transaction log entry showing the notification message initial  generation (that is, in the entry showing the notification message  being enqueued to the process channel). Thus this allows correlating the original message with a corresponding notification message. Note that the presence of two message-id&#x27;s in the message-id field is, also,  a definite indication of MTA generation of a notification message.

Enabling the   MTA option is also helpful when investigating  notification message generation, as it will show the same process  enqueueing the newly generated notification message, and then recording  whatever was the appropriate action on the original message,  e.g., an " " record,  a " " record,  an " " record  (as in the case of a notification due to a Sieve  syntax error report, or message capture notification), etc. (See also the new-in-MS-8.0 " " records.) A point to emphasize here is that the notification message generation,  that is, the enqueue to the process channel, occurs and hence is  recorded before the completion of the operation on the original  message, hence before the recording of what occurred to the original  message.

See also:
 * Notification messages
 * Process and reprocess channels
 * log_message_id MTA Option
 * log_process MTA Option
 * MTA transaction logging