Re: [Exim] MX without A allowed by which RFC's?

Kirill Miazine wrote:

> * John Dalbec [2003-11-19 16:14]:
>
>>What RFC allows an MX record (example.com -> mail.example.com say) to exist
>>without an A record for example.com existing?
>
>
> No RFC forbids such behaviour.
>

Is there an RFC that forbids MTA's from rejecting mail to/from
postmaster@??? because of the above DNS?
Thanks,
John