K F:
> Is it by using debug? How do I set it best to get the smtp statements
> and their responses?
This is not part of routine logging, because it would allow an
adversary to fill your file system with garbage.
Postfix debug logging is for debugging and produces even more output.
That's a way of saying "do not complain about Postfix performance"
if you turn on debug logging.
If you have a business requirement to store SMTP commands routinely,
then I suggest using a network sniffer, or using a reverse proxy
(or load balancer) that does the logging for you. Maybe HaProxy or
Nginx can do that for you.
Wietse
