I have posted earlier too. But I may have more information now or rather, my earlier inferences may not be accurate.

Basically i am running a mail server that does not have that many users per se Around 3000 with 300 or so checking mail daily.
however, given that the virtual server hosts some 50 popular domain names, we get hit by spam and smtp requests like there is no tomorrow.

However, have implemented (or rather piggybacked on someone else's firewall for now).
The problem never happened earlier. its only since last week that it seems someone has discovered us and is trying to bring us down.
But maybe its my configuration that has some holes?

I was wondering if I could post my postfix main.cf and master.cf files out here so anyone can go through it and suggest changes so the system does not die every now and then. When LDAP authentication fails, because of a reason i have not yet pinpointed, users go ballastic.

CAn I post the entire files? or should i only post the non commented lines?

thanks!!
Topcat


ps: even as i wrote this, the loadavg dropped to zero. Did not alert me even when it fell below certain level. nor did it restart ldap. i had to manually do it. basically 30-45 min is what i get before webmail throws me out.

The problem was soft-bounce.

In postfix soft-bounce was on. disabled it and system's been smooth.

Guess is that because of high volume of bad /invalid emails, ldap was brought down to its knees every once in a while. But it never died out completely..