[clamav-users] Occasional sendmail queue delay when using clamav-milter

G.W. Haywood clamav at jubileegroup.co.uk
Tue May 1 12:34:49 EDT 2018

Hi there,

On Tue, 1 May 2018, Aaron Paetznick wrote:

> Occasionally a small percentage of email will seemingly unnecessarily
> get held in the queue when using clamav-milter, although it will get
> delivered successfully on the first attempt with the next queue run. The
> size, time, sender, and recipient all seem to be irrelevant. Our
> work-around is to simply process the queue every 5 minutes, but this is
> not sustainable. We've conclusively narrowed it down to ClamAV, as the
> problem vanishes when we comment out the INPUT_MAIL_FILTER line in our
> sendmail.cf file. Here's that milter line:
> `S=local:/var/run/clamav-milter/clamav-milter.sock, F=T, T=S:4m;R:4m')

The intermittent ones are the trickiest. :(

I haven't seen anything like this issue, although our queues won't be
nearly as busy as yours.

Typically database reloads here (modest hardware) take a couple of
minutes, and your T=S and T=R timeouts for clamav-milter are, like
ours, much longer than that.  But if you have other milters for which
the timeouts are not so long, perhaps it could be an issue.  Even so,
one might then expect that you'd have noticed a correlation with the
reloads, and apparently you haven't.  A puzzle. :)

What log levels are you using for Sendmail and the milters?

Are you using a single clamd instance for all the servers, or one per
server, or ...?

Do you know how long your database reloads take?  Are they reliably
taking that long or do they sometimes stall?

What connections type(s) are you using for clamd?

Have you checked that clamd always responds quickly/reliably to PINGs
on the socket?

Can we take it that you do have enough memory?



More information about the clamav-users mailing list