JHM via Exim-users <exim-users@???> (Mo 08 Nov 2021 14:20:44 CET): > My box runs Devuan Beowulf and within it runs a (VBox) Devuan ascii virtual machine set up
> to start up automatically when I boot.
>
> It is not kept on 24/07 but is booted up a few times every 24 hours.
>
> The Devuan ascii virtual machine runs PI-Hole as a recursive DNS server.
> It is all working as it should but there's a 'snag in the weave' so to speak:
>
> When booting, I'm getting a (not too) short delay at "Starting MTA:" which is when (as I
> understand it) Exim4 does a reverse DNS check.
IMHO Exim doesn't do (reverse) DNS-checks per se. So it depends on your
configuration, whether Exim tries to resolve anything at startup
already.
> The problem is that my DNS (unbound) runs on the Devuan ascii virtual machine which I set
> up to start up automatically at boot but it is not yet up and running when Exim4 does the
> reverse DNS check.
Maybe you can ask your „exim box“ using another resolver and then try to
capture the DNS traffic, to get an idea about the queries that are sent.
Or, simpler, switch on logging on your resolver and check the queries it
receives, if it is Exim, it should either be visible in the resolver
logs, or Exim will write a short notice to its panic- or mainlog.
