Hi Philip
>>temporary *local* problem." I guess, though, that it might be difficult to
>>differentiate between their DNS being broken and the local DNS being broken.
>
>
> Quite. It is hard to generate short warning messages that cover every
> situation. It's a "local" problem in the sense that Exim can't get at
> the data it needs. It can't really tell where that data should come
> from.
That's what I thought. At any rate the other mail admin has been informed about his broken DNS and has agreed that it is a bad thing. Whether he fixes it is something else entirely.
>>Perhaps, if it's not there already, having some options for
>>reverse_host_lookup can be added to the wishlist: e.g.
>>reverse_host_lookup/ignore_servfail
>
>
> The problem is that you can't detect SERVFAIL at the level that Exim
> calls the resolver. The two deferring returns are TRY_AGAIN and
> NO_RECOVERY. In /usr/include/netdb.h, I see this:
>
> #define TRY_AGAIN 2 /* Non-Authoritative Host not found,
> or SERVERFAIL. */
> #define NO_RECOVERY 3 /* Non recoverable errors, FORMERR, REFUSED,
> NOTIMP. */
>
> TRY_AGAIN probably includes cases where the nameserver cannot be
> contacted.
Thanks for the explanation. Also, thanks for Exim: using it has made my job that much easier, challenging and enjoyable -- all at the same time.
Cheers,
Ryan