Author: Ben Giddings Date: To: exim-users Subject: Re: [exim] Very long delay after RCPT
It looks like I solved the problem. It was actually a DNS issue, rather
than an exim issue. Exim was trying to resolve some hosts, was unable
to do so, and bailed out after a while.
I used Tony Finch's suggestion and ran Exim in debugging mode and
watched what happened. I ran it as
exim4 -bd -q30m -d
I know that -bd tries to background it and -d overrides that an
foregrounds it, but I wanted to use nearly the same configuration that
gets used when I ran it from init.d
So, I saw the DNS failures and figured that was the problem.
One question though: does exim cache the results of the DNS lookups it
does? From scanning what was happening, it looked like it was trying to
resolv all the hosts in local_domains etc. multiple times. I hope it
isn't trying to look up that unchanging list every single time an
incoming email arrives. That seems pretty inefficient, if it is the case.
