qmail low concurrency problem -- SLOW! PLEASE HELP
I work for an ISP and we have 4 decent sized servers handling incoming mail. Lately we are having problems with mail floods. We took the usual steps initially to block the higher bandwidth spammers and such, but local queues just grew and grew. I finally looked at the logs and noticed that on all four servers, even though concurrency is set to well above 100 we are only seeing 1 and 2 messages handled at a time. I believe this is causing our problems.
This is causing us some serious problems and I would greatly appreciate any help you could give.