SMTP activity logging tracks SMTP session activity, such as the IP address of the connected client, the number of messages the client sends to the server, the number of bytes the client sends to and receives from the server, the number of recipients to whom messages are sent, and the duration of the session.

There are three types of activity logging records for SMTP sessions:

• Open records, which log when an SMTP session begins
• Checkpoint records, which log activity that occurs when an SMTP session has been open for a specified length of time
• Close records, which consolidate SMTP information into a single record when an SMTP session ends

Related reference
The information in the log file
Example of creating activity logging records