The
problems on their end is that you should not point a domain name (xyz.com) to an
IP address (DNS "A" record), unless that IP address meets one of the following
three requirements:
1. the domain "A" record points to the same IP
address as the domain "MX" record
2. the
domain "A" record is different than the domain "MX" record, but the "A" record
address does not have an SMTP service running on it (this will allow the
delivery attempt to be tried again based on the mail servers queue
timer).
3. the
domain "A" record is different the the domain "MX" record, but the domain "A"
record is either setup as a secondary "MX" or at a minimum the SMTP service
that's running on it will accept and relay for the domain (otherwise once the
refusal to relay message is sent back to the sending mail server, the e-mail is
immediately returned to the sender with no more retries).
Bill
-----Original Message-----
From: Len Conrad [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, December 01, 1999 11:24 AM
To: [EMAIL PROTECTED]
Subject: RE: [IMail Forum] delivery to A recordsI have experience this problem, as well (see example log entry below). In
this case the "A" record for paml.com points to their web server and not the
same IP address and "A" record as the "MX record, which points to
mail.paml.com.
Well, what's the pb? the domain.com and the mail.domain.com are two different ip's, maybe two different machines. sounds like valid, even recommendable, idea, to me.
And to make things worse, the web servers appears to be
running an SMTP service, as well, but which refuses to relay for the domain
paml.com
I've read recently that some MTA's, having failed to deliver to the primary MX ip, will try domain's ip itself. ie, MX ip, and then A ip, but what about the MX secondary ip's? Are is there only one MX for the domain?
(I know, this is really a problem with the way they have things
setup on their end,
why is it a pb on there end? what's invalid?
If their domain.com really has an SMTP service running when it shouldn't be, then that's wrong, and I bet they don't even know it's running. The above behaviour of some MTA's trying the main domain.com ip will cause pb's.
but the reality is that we have to deal with these kinds
of problems everyday). If there is a way to disable the "A" record delivery
attempts, please let us know how to do it.
It's a behaviour by the sending MTA, so you have to run the pb by the admin there.
Len
