I'm not sure if there are any addresses without numbers. I will check into that furher. Below I've included part of the header for a successful email using webmail, and below that an example of a problem one using an email client. The key must be in there somewhere...What does webmail do differently? Thanks again for your help....

Part of the header to a successful email to microplay.ca domain using webmail:

X-Apparently-To: encoregames@rogers.com via 206.190.37.189; Thu, 10 Feb 2011 14:36:08 -0800
X-YahooFilteredBulk: 207.96.250.22
Received-SPF: none (mta1012.rog.mail.sp1.yahoo.com: domain of 00749@microplay.ca does not designate permitted sender hosts)
X-YMailISG: Bz6D_TccZArZd3X6XCs8b8RhI64QCj8OTDQdRUzOKDvqrNKW
bd0F9ETuvwXgDGP72HDu6uc7gfyX7x2IBUgIbRKzVJUZjzDzkw p7eCtSOr25
8j6VtnhTY4Cii_uCCdU.gKTpoOpYrZB3zITmBAdY4kYD85mK2W nSV80G8M3C
pfAceN1.fdHhVpYV1xwX.b0j_ahV0bAeUc_NZS7XRDu0FCiTZU oPsG04PTfr
YwXJJz.Gd3m0Li9UflaLz60f.NkycqTbczezHTpCxqa0N1Yzjh _H7qG_Ssyg
EqSpOGkao8sh_ghHr08oTloBSN4FaG6PK3nxgdOIYjG_nSuaVJ iUtr1HBJHQ
2xbEvJ8Pt5ypMcl.F81g.ILeKIjRrTrOd5z3p74E2JBXmeYnr8 C3ZEtKdhjZ
sh6jXqIWc3nv7WRYdXzJ6ABq4AM4A6j_ZWMMNIxYUwt_gfKirI tA14TJJqr3
4FOovSpsOPEENpDief97SsjaqJ186iEfN68WSxe03Ko2vxejpk VVZOzE5w4h
ymo28F2InZhW1o5zq_ki585UVUs5z9EMpnS7ftZ7Rc0q4ILA_h j56RXzldTa
93A-
X-Originating-IP: [207.96.250.22]


Authentication-Results: mta1012.rog.mail.sp1.yahoo.com from=rogers.com; domainkeys=pass (ok); from=rogers.com; dkim=pass (ok)
Received: from 207.96.250.22 (EHLO mail.lesuperclub.ca) (207.96.250.22)
by mta1012.rog.mail.sp1.yahoo.com with SMTP; Thu, 10 Feb 2011 14:36:07 -0800

Part of header for problem email:

Hi. This is the qmail-send program at yahoo.com.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<00750@microplay.ca>:
Connected to 207.96.250.22 but connection died. Possible duplicate! (#4.4.2) I'm not going to try again; this message has been in the queue too long.

--- Below this line is a copy of the message.

Return-Path: <encoregames@rogers.com>
Received: (qmail 76431 invoked from network); 9 Feb 2011 23:35:59 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024; d=rogers.com;
h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subjectate:Message-ID:MIME-Version:Content-Type:X-Mailer:Thread-Index:Content-Language;
b=0Eh/g4kmpZ3CVHfordOLmk9LXtSK4YPK0x5dk3anaSvak5E9IQv5Q7 O9ihddF9r76rthI3qgCqpZaN5z4tku3k7RmwEnao6peCXXkJ1o mPFChW/SzeRYtP+iWSm3ZMAdMGsMbNRjDkVsIHfm16epGR6teto54SrSs 7N3CjC2NVA= ;
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rogers.com; s=s1024; t=1297294559; bh=6yP1pKJ4JbMpIYfWH5PKknlQzGucXmkpPX2UllXROuk=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:From:To:Subjectate:Message-ID:MIME-Version:Content-Type:X-Mailer:Thread-Index:Content-Language; b=z4b3mnmjrE3vvHSQKpie9NVKx5eFk0qEET4/atGB5bsqFo90vofUx247NCejgWXaWBTmOzjgWbW9+nxaoUFZVO 0ro7A2VlZ9TeGOVP0sSvk/oznq5b0IY+yD2GQ9TzmSkV/M/pv4kKGRCo/OozUkX0rcYE7vGwIEvSACHV4zPak=
Received: from BrianInthofPC (encoregames@99.254.168.226 with login)
by smtp107.rog.mail.re2.yahoo.com with SMTP; 09 Feb 2011 15:35:56 -0800 PST
X-Yahoo-SMTP: cfGCsk2swBCPx347qTCdvaZ5FeTQjjnNMd_iC9TrxoLeJpI-
X-YMail-OSG: 7OkBWpsVM1n_8jIKTsr7wvWbZyhvbPeDtIBGVdJ5nbIPRfN
CaJX.JCIoPwhcFCmKG9MxW6Wpxuo1zfvoiEKtol2772CbfG5Ap q.k2A60VIO
h4ZAhnvcpyDrqQTQt3xGXa2ZVl7mjzTDmqRtU4tFegMiVh8TlW ylUWcK_1hn
.Zj2k6Kf1PUEOwzSmCjJOiU73URwE88txGLCdwD92s3J9eU6iQ ZpfmLibc8F
aV7w4gT20JQ--
X-Yahoo-Newman-Property: ymail-3
From: "Encore Games \(Microplay\)" <encoregames@rogers.com>
To: "'Microplay Kitchener'" <00750@microplay.ca>
Subject: test
Date: Wed, 9 Feb 2011 18:35:54 -0500
Message-ID: <000001cbc8b2$1872ed30$4958c790$@com>
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0001_01CBC888.2F9CE530"
X-Mailer: Microsoft Office Outlook 12.0
Thread-Index: AcvIshgdQC/mLmF+SxafYx1uM+99VQ==
Content-Language: en-ca

This is a multi-part message in MIME format.

------=_NextPart_000_0001_01CBC888.2F9CE530
Content-Type: text/plain;
charset="us-ascii"
Content-Transfer-Encoding: 7bit

A little hard to tell from those headers - and they apparently aren't complete - but it looks like it's actually your ISP (Superclub?) who is rejecting the message. Maybe their SMTP queues aren't configured correctly?

Also, who hosts your microplay.ca server? Is that Rogers also or do you have a 3rd party hosting?

Well, my HO is investigating the problem again, apparently they are going to look into the mail servers. I guess I will have to wait patiently for their analysis. I tried to get information on who hosts the server but they didn't tell me, they just replied that I've got a ticket number and that they're on it. I will post the resolution if and when they find it...(BIG if)

Ok, I think I'm on to something but I'm not sure yet why it is happening or how to fix it. The main part of the error message I get back is this:

Connected to 207.96.250.22 but connection died. Possible duplicate! (#4.4.2) I'm not going to try again; this message has been in the queue too long.

It appears that this IP is called Kerio Mail Server 6, and when I type it directly into explorer it takes me to a page asking for a username and password. I suppose that would explain why it times out after a day....the page is waiting for user input and never gets it, so it eventually dies. But I what I need to know is WHY is my message going to this server and why are only microplay.ca domain names doing this and being affected. And how do I stop it from doing this? Any thoughts?

I have discovered that 207.96.250.22 is a Superclub/microlay server, but according to my HO, the email never arrives. This is what HO said:

Despite what Rogers says, on our end, these emails never even got to our server. If they were refused we would have seen them in the logs, which for these ones would have been a huge surprise since we asked for our server to accept all emails from Rogers and Yahoo, but as I said, they didn't get to our server. We also looked at the knowledge base of our email server software, there is no entry relating to problems similar to yours. As such, the router settings and the anti-virus email scan that you mentionned are the most likely problems.

So why would the message not actually get to the server? It can't be my anti-virus, because I've disabled it, uninstalled it, reinstalled new software and so on, all the time sending test emails, but the problem persists. If it is a router setting, why is only one domain affected? Any further help would be appreciated, though I realize that this is now out of the domain of being an "outlook" problem.