Re: [exim] Setting helo_data correctly for multi-homed hosts

* Jakob Hirsch:

> Florian Weimer wrote:
>
>> I'm trying to work-around the A/AAAA bug, which means that I must add
>> separate MX entries for the v4 and v6 interface. As a result, I
>
> As I understood, it should only happen if the DNS records have different
> TTLs, or am I mistaken?

No, it also happens when something does an AAAA lookup without an A
lookup (or vice versa). The TTL is decremented in the resolver, and
its value depends on the age of the record in the cache.

> But I don't see why you should do this. You could use a general name
> mxout.example.com, let mxout.example.com have your ipv4 and 6 address
> and add mxout to the rDNS.

Ah, indeed, this will work. Proper reverse lookup is desirable for
outgoing mail only, and not for incoming mail.