On Sun, May 13, 2001 at 10:24:24AM +0530, Suresh Ramasubramanian wrote:
> Using a large mallet, Duke Normandin whacked out:
>
> > You are correct as per the SMTP protocol and the relevant RFCs.
> > However it's my understanding from a very recent thread on the
> > FreeBSD-questions list, that the SMTP 'fact-of-life' is that unless
> > your IP/Doamin name resolve both ways, an increasing number of
> > servers will refuse your mail.
>
> Precisely. And this is sad. I would do this myself (reject mail from
> IPs with no forward / reverse dns - _not_ forward and reverse
> mismatches like some do) -
I take that by "mismatches" you mean an almost correct match on the RDNS.
In this day-and-age, 'almost' _is not_ good enough. The suckers _had_
better resolve. The implications of this whole thread for some Mutt users
is important. If a user, like myself, is running Mutt on Cygwin, AND is
on a dial-up, AND for some reason needs to run a SMTP server to accept
local mail from more one MUA, he cannot run the server "end-to-end"
because given his dyn. IP, his outbound mail will always be rejected
because RDNS never resolves. Hence, the need to use the 'From' thing in
/etc/muttrc, AND to "relay" your outbound to your ISP. HELO had better be
'yourISP.whatever' for your outbound to get through -- mismatches don't
count.
If you're running SMTP as both server and client, i.e., you have an IP
and a domain that resolve both ways, then how you handle inbound stuff is
up to you. Like I said though, increasingly, your outbound needs to
resolve on RDNS --- sad, but a fact. So this second scenario _also_ has
implications as to how Mutt is set up.
have I missed something obvious here?
--
-duke
Calgary, Alberta, Canada
