Re: [exim] Trouble receiving from hotmail

Hi Aaron, on Tue, 12 Oct 2004 16:45:24 -0400 you wrote:

> I'm running Exim (4.30-25.2) and SuSE 9.1 with Mailman (2.1.4) and I'm
> having trouble getting mail in from Hotmail.

[...]

> 2004-10-12 16:21:11 no IP address found for host
> bay13-f3.bay13.hotmail.com (during SMTP connection from [64.4.31.3])
> 2004-10-12 16:21:11 H=(hotmail.com) [64.4.31.3] sender verify fail for
> <ahc1979@???>: Unrouteable address
> 2004-10-12 16:21:11 H=(hotmail.com) [64.4.31.3] F=<ahc1979@???>
> rejected RCPT
> <mailman-itd-confirm+68cabddc145e5ef92bdeae593afa268a313e562a@???.
> org>: Sender verify failed

> It looks to me like the reverse DNS check is upset since the
> reverse DNS name doesn't match the domain name perfectly,

No; the line there about "no IP address found for host" is informational
only; it's not the reason for rejection.

> or it's timing out too quickly. Can anyone give me a suggestion on
> where to start?

"Sender verify failed" is the reason for rejection, as you can see from
the log line. What this means is that Exim has run through what it would
do to route mail to "hotmail.com" and has decided that it's impossible, so
the sender is rejected as invalid.

Some reasons for this:

a) Hotmail's DNS is screwed up big time. Probably unlikely.

b) Your DNS is screwed up big time. Possible, especially given the reverse
DNS failure. (The IP in question looks up OK from here, at least now).
Note that if there was just a temporary error resolving a name (e.g. if
your DNS server was down) then that wouldn't result in a permanent
rejection of the mail; it would be temporarily rejected and the sending
server would try again later. However in your case the mail has been
permanently rejected.

c) You have done something wrong in your config which means that Exim is
trying to route mail to "hotmail.com" via a non-standard method (i.e. you
have put in some router which is incorrectly catching mail for
hotmail.com) and this method is failing. If you've just been setting up
mailman, you've presumably been adding routers and so on, so it's possible
you've erred.

In any case, Exim provides fantastic debugging tools which make solving
problems like this a breeze. Just do:

exim -bt <some address>@hotmail.com

and that will give you a quick run down of how Exim reckons <some
address>@hotmail.com should be routed. If that's not enough, do:

exim -d -bt <some address>@hotmail.com

and you'll get very detailed and verbose (but highly logical and
structured) debugging output - just trace through it until you find the
point where the problem is occurring.

> I don't get anything back at Hotmail.

Hotmail is screwed then. Not that it isn't anyway; for example (as has
been demonstrated on this list), they inexplicably ignore basic things
like adding References: or In-Reply-To: headers when their users reply to
e-mails, which is totally unnecessary, very annoying and screws up
threading.

Tim