Windows mail not sending. What does this error message mean?

[TraGreg]

Suddenly my email won't send. I have Windows Mail and have not made any setting changes. Here's the message that comes back to me. Can anyone tell me what's wrong?

Hi. This is the qmail-send program at hosting2.surfmerchants.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.

<mjdolan1@yahoo.com>:
216.39.53.2 failed after I sent the message.
Remote host said: 554 Message not allowed - UP Email not accepted for policy reasons. Please visit http://help.yahoo.com/help/us/mail/defer/defer-04.html[120]

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

Return-Path: <KSSTracyZ@kernscheduling.com>
Received: (qmail 32180 invoked from network); 19 Feb 2008 20:03:13 -0500
Received: from cpe-69-207-42-164.buffalo.res.rr.com (HELO TracyPC) (69.207.42.164)
by u15197719.onlinehome-server.com with SMTP; 19 Feb 2008 20:03:13 -0500
Message-ID: <22C7F99BE6CA4BF29076B1CF9F972A6A@TracyPC>
From: <KSSTracyZ@kernscheduling.com>
To: <janedoe@yahoo.com>
References: <200802191301.m1JD1Ws2007815@bdc.sassieshop.com>
In-Reply-To: <200802191301.m1JD1Ws2007815@bdc.sassieshop.com>
Subject: Re: SHOPPER CONTACT : Jane Doe Date: Tue, 19 Feb 2008 20:03:09 -0500
MIME-Version: 1.0
Content-Type: text/plain;
format=flowed;
charset="iso-8859-1";
reply-type=original
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Windows Mail 6.0.6000.20661
X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545

[Gnomad]

Because the message is tagged as spam by Yahoo.

[Miz]

If you go to the link to the Yahoo page that's in the error message (and your post), you'll find a link to contact Yahoo to explain and find out why the message is being refused.

[TraGreg]

Thanks so much. That does make sense. I contacted Yahoo about it through the link in the error message (duh) and the only question I didn't know how to answer was What domain(s)? What is that and how do I find it? Thanks so much.