Marc Sherman wrote:
>
> FYI, the requirement that the PTR and A records must match is in RFC
> 1912, section 2.1, paragraph 2.
>
Well, if I summarize RFC
RFC1912 section 2.1, paragraph 2
Also,
PTR records must point back to a valid A record, not a alias defined
by a CNAME.
RFC2821 section 3.6
The domain name given in the EHLO command MUST BE either a primary
host name (a domain name that resolves to an A RR) or, if the host
has no name, an address literal as described in section 4.1.1.1.
RFC2821 section 4.1.1, paragraph 6
An SMTP server MAY verify that the domain name parameter in the EHLO
command actually corresponds to the IP address of the client.
However, the server MUST NOT refuse to accept a message for this
reason if the verification fails
That means if a mail server has a PTR of
123.123.123.123.dynamic.example.net, that
123.123.123.123.dynamic.example.net resolves to its IP, and server
HELOes with
www.google.com. The remote mail server MUST NOT reject the
message based on this info.
Can someone cancel this by citing another RFC?
