[Mimedefang] Greylisting problem with the default confTO_COMMAND

[Cahya Wirawan]

Hi,
I have implemented greylisting in filter_begin, it works great,
but there is still an issue because there are some spam software
that keep the connection open after they get temporary failure message.
The sendmail default timeout to wait a command (confTO_COMMAND) is
1 hour, so if I set the max mimedefang processes and sendmail children 
to 50 (I think this is not too small for 30k mails/day), the mail relay 
will be often out of processes and can't accept any new mail because
all 50 sendmail processes are used by mail clients that don't quit
immediately after tempfailed. 
so I changed confTO_COMMAND to 5 minutes, and it helps, but I am not
sure if it is ok. and actually not only some spam software keep the
connection open after tempfailed, but I have seen also email from
checkpoint.com that wait for an hour till disconnected by sendmail.
I don't know which mail server do checkpoint use and if it understand
that its mail get tempfailed by our mail relay.
So I hope someone know about this issue.

thanks,
cahya.