Matthias-Christian Ott <ott@???> (So 10 Okt 2010 23:05:40 CEST):
> example.com. IN CNAME b.example.com.
> example.com. IN MX 10 mx.example.com.
> b.example.com. IN A 198.51.100.2
> mx.example.com. IN A 198.51.100.3
>
> According to RFC 1912 there can't be other RRs if there's already a
> CNAME. It seems some SMTP servers followed the DNS RFC very closely and
… That's what some of the RFCs are for, I'd say.
> didn't send E-Mails at all. But this doesn't explain why that particular
> SMTP server rewrote the recipient (after I added a transitional MX
> record for b.example.com ebay.com did the same).
Yes, this behaviour is expected - I think, some SENDMAILs rewrite the
envelope if they're faced with CNAMES in domain names or mx records.
You can't do anything against this, other than not using CNAMEs at all.
--
Heiko
