Slow (30 sec) response to incoming SMTP connection

[ranageman]

Incoming SMTP connections are always taking 30 seconds, or just over, to connect. This is causing problems with some senders who have their timeout set to 30 seconds.

While waiting, the following process is running:

root 30626 25648 0 12:14 ? 00:00:00 tcp-env /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true

Here is a debug log from a sender with a simple Perl Net::SMTP connect:

[dan@frame-1 bin]$ time ./smtp_test.pl
Net::SMTP>>> Net::SMTP(2.26)
Net::SMTP>>> Net::Cmd(2.24)
Net::SMTP>>> Exporter(5.566)
Net::SMTP>>> IO::Socket::INET(1.26)
Net::SMTP>>> IO::Socket(1.27)
Net::SMTP>>> IO::Handle(1.21)

<wait 30 secs>

Net::SMTP=GLOB(0x127128)<<< 220 39151.vs.webtropia.com ESMTP
..etc.

Connection is successful.

What might be waiting 30 seconds here?

/ranageman

 

[ranageman]

Ha - fixed it myself

Put a "-R" as the first item in "server_args" in /etc/xinet.d/smtp_psa, and restarted xinetd.

Apparently smtpd will otherwise wait up to 30s for (useless) remote info from the incoming server, and in my case here, the incoming server timeout was set to about the same....