It's possible that amavisd slows down your postfix. You can try to increase the number of amavis processes in the config:
$max_servers = 5; # number of pre-forked children The number of amavisd processes is independent of the smtp processes. On Thu, Nov 17, 2011 at 7:15 AM, Alex <mysqlstud...@gmail.com> wrote: > Hi, > > >> I built a dual-Xeon quad-core box with 8GB using fedora15 and > >> postfix-v2.8.5 and during various times during the day connections to > >> port 25 timeout or are very slow. The majority of times this happens > >> is under peak loads, but even times when it's not at capacity it may > >> do this. > > > > Often slow smtpd connections are caused by not having enough smtpd > > processes running. > > > > On your hardware, postfix will support thousands of smtpd processes. > > Use netstat or lsof to see how many connections postfix is handling > > when you experience slowdowns. > > It's in the hundreds. There is also some amount of iowait, but I don't > think that's the issue. > > When using amavisd-new, shouldn't the number of processes match the > number of smtpd processes? > > I think what I'm concerned about is having postfix receive more > messages than amavisd can process? > > > If zombie spambots are using up most of your available connections, > > postscreen will likely help. > > http://www.postfix.org/POSTSCREEN_README.html > > Yes, looks like this would be a good thing to do is a general idea. > > Thanks again, > Alex >
