[69311] in North American Network Operators' Group
Re: Mailserver requirements
daemon@ATHENA.MIT.EDU (Richard Welty)
Mon Apr 5 17:51:00 2004
Date: Mon, 5 Apr 2004 17:48:19 -0400 (EDT)
From: Richard Welty <rwelty@averillpark.net>
To: NANOG <nanog@nanog.org>
In-Reply-To: <4071D058.7060806@nipper.de>
Errors-To: owner-nanog-outgoing@merit.edu
On Mon, 05 Apr 2004 23:32:08 +0200 Arnold Nipper <arnold@nipper.de> wrote:
> On 05.04.2004 23:18 Mike Walter wrote:
> > I am surprised you don't have problems sending to AOL as well.
> > They don't accept email from servers that do not have reverse addresses.
> > I don't accept email from severs without reverse addressing.
> of course this server does have a reverse mapping. But this reverse
> mapped doamin does not have an MX record.
yes, and that's what's wacky. there is no requirement in the RFCs that
i'm aware of that mail senders have MX records pointing back at them.
there's not even a requirement for MX records for a domain, the SMTP
RFCs clearly indicate that in the absense of an MX record, an A record
will suffice.
for that matter, if i were running a very very large mail farm with high
volume in one or both directions, separating the inbound mail handlers
(MX hosts) from the outbound mail relays would be something that i'd
seriously consider doing as part of the architecture. this would interact
very badly with the mail rejection strategy outlined in the original post
in this thread.
richard
--
Richard Welty rwelty@averillpark.net
Averill Park Networking 518-573-7592
Java, PHP, PostgreSQL, Unix, Linux, IP Network Engineering, Security
