Re: Paul's Mailfrom (Was: IETF SMTP Working Group Proposal at smtpng.org)

[Scott Gifford <sgifford () suspectclass com>]

Brad Knowles <brad.knowles () skynet be> writes:

[...]

>       Moreover, even if all servers on the Internet were secured in
> this manner and there were no open relays, it would also require
> perfect reverse DNS because the MXes are listed by name and not IP
> address -- that's assuming you do a reverse lookup on the IP address
> and require that the returned name is on the list.

The proposal suggests that you get all of the A records for all of the
accepted names, then make sure that one of the A records matches the
address that the connection came from.  See sec. 2.3.

Even if it did require good reverse DNS, that would only be needed for
domains that chose to implement this, and only for addresses that
are allowed to send mail from that domain.

----ScottG.