SMTPdiag and SOA

When I run smtpdiag I get a couple errors. (Exchange 2003/SBS 2003)

Checking MX servers listed for
Connecting to [] on port 25.
Error: Expected "250". Server rejected the recipient address.
Failed to submit mail to

For the most part, email works. But there are a couple domains we can't email into. I'd like to understand and clear up that error message as a troubleshooting start....what does that mean?
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It means that the mail server "" rejected the recipient address you used in smtpdiag. Most likely this server doesn't know it is responsible for this domain or the user (hence the e-mail address) doesn't exist. If the e-mail address you used exists, the server is mis-configured. Else, try another e-mail address for testing; one you know it exists.

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It means when it tried to deliver a message to a test recipient at the domain name, it failed as the server rejected the recipient address.

What email did you use as 'recipient' for the test? Is this domain in the Exchange 2003 recipient policy as an accepted domain name?

Alan HardistyCo-OwnerCommented:
Please check your server settings / domain settings against my Article about problems sending mail to one or more domains - it might throw up the reason why you are having problems:
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