[exim] Re: No route to host for sesame.csx.cam.ac.uk?

Marc Sherman wrote:
> I just got a strange message in my mainlog when mailing to the
> exim-users list:
>
> 2005-01-07 14:45:12 1Cn02g-0000Ki-7d sesame.csx.cam.ac.uk
> [2001:630:200:8080:20e:cff:fe09:a58a]: No route to host
>
> I suspect that this is because sesame has an AAAA record in DNS, and
> exim is compiled/configured to use IPv6, but my host doesn't actually
> have an IPv6-capable connection to the internet. Is that correct?
>
> If so, is the correct solution "dns_ipv4_lookup = *" ?

I posted this a week and a half ago, and Tony Finch confirmed that this
was the correct solution (or, alternatively, just ignore the message).

However, I've been running with that setting since then, but I'm still
seeing those messages occasionally. I'm currently running exim 4.34
(yeah, yeah, I know, Debian... :) Was there by any chance a known bug
with this setting in previous versions?

I could easily just ignore the message, but if I can avoid the
performance hit of making an AAAA query that I know will ultimately
fail, I'd like to.

Thanks,
- Marc