there exists also a "SMTP Send Protocol Log" which is based on the same format and "Message Tracking Logs" with the following fields:
#Software: Microsoft Exchange Server
#Version: 8.0.0.0
#Log-type: Message Tracking Log
#Date: 2009-09-21T00:02:29.040Z
#Fields: date-time,client-ip,client-hostname,server-ip,server-hostname,source-context,connector-id,source,event-id,internal-message-id,message-id,recipient-address,recipient-status,total-bytes,recipient-count,related-recipient-address,reference,message-subject,sender-address,return-path,message-info