Luigi Rosa:
> The documentation says
>
> "The address type ("ipv6", "ipv4" or "any") that the Postfix SMTP client will
> try first, when a destination has IPv6 and IPv4 addresses with equal MX
> preference."
>
> What exacly happens if example.com has
>
> example.com. IN MX 10 mail.example.com.
> mail.example.com. IN A 1.2.3.4
> mail.example.com. IN AAAA 2001:1234:abcd::beef
>
> and
>
> smtp_address_preference = any
>
>
> What protocol is tried first with "any" setting?
Oh ye of little faith. The answer is: any. Postfix makes a random
choice.
This is the safest choice, because it prevents mail from getting
stuck when IPv4 or IPv6 is unavailable, as long as one of them
works.
Wietse
