Exchange Server Email problems - any experts?

[andyw]

Guys/Gals,

Hope someone can help here, pulling my hair out.

Emails from one of our customers are not being delivered to our server, they have no problems with any other suppliers.

We can send emails to them and they recieve, however when they reply nothing comes through, I have gone through the logical diagnosis procedure but and baffled now!!

Both running MS Exchange ours is v5.5 fully patched- their's is v6 - nothing software or hardware changed on either site, just stopped "overnight"

Anyone suggest what else I can check

 

[frog1520]

Whats in the headers mate?

Do they bounce?

Are they queued up on the clients server?

Anything in the client's server logs?

 

[andyw]

ok - bit more information from the customer (in USA so they are still working)

they are getting an undeliverable report back from THEIR server, not ours - nothing at the client server whatsoever, nothing in the queues, nothing in the logs

no headers on the undeliverable as it seems it isn't resolving at their end...

they have pinged our server - it resolves the ip but times out, I have pinged their server from our end - exactly the same result, resolves but times out...

(thanks frog!)

 

[frog1520]

What does the undeliverable report say at their end?

From what you're saying it sounds like DNS is resolving OK, but from thereafter the connectivity is broken. Having said that - have you tried pings before to this server and do they usually work? Sometimes they're blocked by the routers.

I think the key is what the undeliverable message says. If their server cant send to yours and so returns the message, it should give an indication of what its problem is. One would hope anyway...?!

 

[frog1520]

By the way, are you getting incomming emails from anywhere else?

If you PM me an email address to try, I'll see how its looking externally if you want....

 

[andyw]

What does the undeliverable report say at their end?

From what you're saying it sounds like DNS is resolving OK, but from thereafter the connectivity is broken. Having said that - have you tried pings before to this server and do they usually work? Sometimes they're blocked by the routers.

I think the key is what the undeliverable message says. If their server cant send to yours and so returns the message, it should give an indication of what its problem is. One would hope anyway...?!

this is what they sent me,

Subject: Mail Problems
Date: Tue, 16 May 2006 10:21:40 -0500
MIME-Version: 1.0
Received: from mx2.boelter.com ([207.170.16.75]) by
bay0-mc3-f10.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.1830);
Tue, 16
May 2006 08:18:37 -0700
Received: from mkemail01.boelter.local (unknown [10.1.20.25])by
mx2.boelter.com (Spam Firewall) with ESMTP id 9D65F25343for
<email addy was here!>; Tue, 16 May 2006 10:18:03 -0500 (CDT)
X-Message-Info: LsUYwwHHNt0JSaZBxI0KJR7pF0+DU0aqwvwAGU3DDYc=
X-ASG-Debug-ID: 1147792683-13380-10-0
X-Barracuda-URL: http://10.1.10.19:8000/cgi-bin/mark.cgi
X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0
Content-class: urn:content-classes:message
X-ASG-Orig-Subj: Mail Problems
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
Thread-Topic: Mail Problems
Thread-Index: AcZ4/G6bxkVNV74PRMCJ2nq1hBxzQQ==
X-Virus-Scanned: by Barracuda Spam Firewall at boelter.com
X-Barracuda-Spam-Score: -1002.00
X-Barracuda-Spam-Status: No, SCORE=-1002.00 using global scores of
TAG_LEVEL=1000.0 QUARANTINE_LEVEL=1000.0 KILL_LEVEL=1000.0
X-Barracuda-Rcpt: email addy was here
Return-Path: email addy was here
X-OriginalArrivalTime: 16 May 2006 15:18:38.0767 (UTC)
FILETIME=[0205E3F0:01C678FC]

 

[andyw]

By the way, are you getting incomming emails from anywhere else?

If you PM me an email address to try, I'll see how its looking externally if you want....

yes we are receiving mail as usual from elsewhere

 

[frog1520]

Any attachment with that mate? Doesn't give a lot of info does it

 

[andyw]

Any attachment with that mate? Doesn't give a lot of info does it

no it doesn't - and that was all he gets!

 

[frog1520]

no it doesn't - and that was all he gets!

Sommat odd going on mate. After looking at your PM and checking out your end, something looks buggered at theirs. But its not possible to test their end in the same way because you can only externally test the recipient, not the sender.

That mail you got doesnt look like its generated by a mail server reporting a problem - they dont usually have subject 'Mail Problems'. I know getting info out of clients is like pulling teeth sometimes. There must also be something in the server logs at their end - if it bounces a mail back, it should log it somewhere.....

 

[league67]

andy

how much access do you have on 'their' site ? Get someone to from 'there' (ideally from their xs) to telnet to you exchange server (port 25) and see if you get connection

 

[andyw]

how much access do you have on 'their' site ? Get someone to from 'there' (ideally from their xs) to telnet to you exchange server (port 25) and see if you get connection

have mailed them with this request and further info from their server also

Thanks



Andy

PS, no doubt i'll be back for further help

 

[sasha]

firewall

 

[league67]

np

If you email me your xs address I can try to telnet from here (have both xs and qmail) and tell you if I can see something.

Regards

 

[frog1520]

firewall

Apparently mail is reaching other sites without a problem so outgoing port 25 shouldnt be blocked on the firewall or all mail would fail. Of course they could have just blocked andy's site, but no idea why someone would do such a thing.

 

[andyw]

If you email me your xs address I can try to telnet from here (have both xs and qmail) and tell you if I can see something.

Regards

I think frog has done this for me already? Thanks for the offer

This is a great forum!

 

[frog1520]

I think frog has done this for me already? Thanks for the offer

This is a great forum!

Yep - Looked fine to me!

 

[WLeg]

Their Barracuda Firewall / Spam filter is blocking the messages.

 

[frog1520]

Their Barracuda Firewall / Spam filter is blocking the messages.

Interesting! Why do you say that?

 

[Sp!ke]

My first thoughts would be the same since the message is not strictly a bounce message but a reply from their filtering software. Looks to me like the mail gets no further than their local mkemail01.boelter server.

I think they need to look in their Barracuda logs to find out what is going on in the first instamce. Perhaps there is an access control list or string in the address that Barracuda doesnt like.