Is this my server's problem, or something wrong with the sender? If
it's mine, how do I fix it and keep it from happening again?

NT4 SP6 server running Exchange 5.5, SP4. All my tests are fine. I
have a 6 gig drive broken into 2 partitions: 2 gig for the system, 75%
free, and 4 gig for Exchange, 60% free. I can email my users
perfectly, with attachments, from 3 different outside email accounts.
There are no limits on message size that I can see. Event Viewer
Message 1221 says that I have 450 megs free in the private
store, which is 1.5 gig. I ran the eseutil on the private store last
night.

A outside client tries to email my users. No attachment. Everything he
sends to us gets bounced back to him with the below error messages. He
and a user both say that others are having the same problem, though I
can't reproduce it. Other ousiders seem to be getting through fine.
The sender says he can email other people fine.

My questions are:

1) Is it my problem? If so, how do I fix it? How can I prevent this
from happening again? MS seems to say that eseutil is not required
maintenance.

2) Did my server produce the below error message, given to me by the
problem sender?

3) Who is usr227174110@Xinstitute.com?

Thanks all for any insight. My googlegroups and KB searches come up
with
nil, other than the eseutil, which doesn't help...

======================================
From: Mail Administrator [mailto:Postmaster@Xinstitute.com]
Sent: Monday, October 07, 2002 2:23 PM
To: karl@Xcircuits.com
Subject: Mail System Error - Returned Mail


This Message was undeliverable due to the following reason:

The user(s) account is temporarily over the storage quota.

<usr227174110@Xinstitute.com>

Please reply to Postmaster@Xinstitute.com
if you feel this message to be in error.
======================================================== 
The problem sender gave me this info as well, as a .dat attachmant
that came with his error message:
==============================================
Reporting-MTA: dns; imta02a2.registeredsite.com
Arrival-Date: Mon, 7 Oct 2002 17:23:06 -0400
Received-From-MTA: dns; Sales4 (66.236.59.34)

Final-Recipient: RFC822; <natchezs@Xinstitute.com>
Action: failed
Status: 4.2.2
X-Actual-Recipient: RFC822; <usr227174110@Xinstitute.com>
===============================================

That's me as the Final-Recipient. Still don't know about usr227174110.
Who is the Reporting and Received-From MTA's?

---

Clarification of Question by amohat-ga on 11 Oct 2002 16:16 PDT

I'm closing this question because I figured it out, but since google
says it will still be listed, here's the answer...and it's obscure,
just like I thought:

I'm an Interland customer; they host my website and are the
authoratative name server for my domain. Seems that the only people
who can't email me are OTHER Interland customers.

Get this-when they set my account up, they also setup complimentary
pop3 email accounts on their mail server, which coincidentally runs
2nd in my mx listing behind my Exchange server.

So THOSE accounts were full, or malfunctioning at any rate. And email
sent from WITHIN Interland's network BYPASSES the normal procedure
that OUTSIDE email uses!!!

So it is NOT my server! Yay!

It's not their server! Cool.

It is Interland's server / system! Argh!!!!!

Interland's Khadejam (cool name), tech support, answered my call
quickly, knew my problem right away, and made the motions to have it
taken care of in 48 hours at the latest. Those motions being to clear
and de-provision the pop3 account(s) and delete the secondary mx
record from my DNS entry.

Now I want my week of anguish back...