The Path to Zen

Qmail And Its 30 seconds SMTP delay

On this new server I’ve got, Horde is configured to use the qmail smtp demon on localhost to send emails. Qmail is pre-configured by Plesk. I ran into this mysterious delay every time when I tried to send an email from Horde. When I opened up each test message source from the receiving end, the headers would show exactly a 30 seconds delay for the “localhost hop”. That smelled like some kind of timeout to me… and a bit digging into qmail’s documentation proved it - qmail’s tcp-env would time out after 30 seconds when trying to get the TCPREMOTEINFO data from the remote host. And tcp-env is exactly what xinetd uses to drive qmail-smtpd everytime there is an smtp connection comes in.

So in case you are running into the same problem, here’s the solution - go to /etc/xinet.d, open up smtp_psa, and add a “-R” to the beginning of server_args. Then “ps -e | grep xinetd” to get the pid of xinetd, and “kill -USR2 <the pid>” to put the config change into effect.