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troubleshooting Question

SMTP communication error 550 and 503 from Exchange 2003

Avatar of fi8224
fi8224 asked on
ExchangeSBSEmail Protocols
6 Comments1 Solution2373 ViewsLast Modified:
I'm a computer consultant and one of my clients is getting a few email bounce back messages when dealing with a particular business associate. We are using 2003 SBS . We are also using Ninja. I have checked the spam services, and the ISP for blacklist issues. The two different bounce backs may be unrelated. I will post both bounce backs here. The names are changed to protect the innocent.
 'username@egsllp.com' on 2/2/2007 9:58 AM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            <mydomainname.com #5.5.0 smtp;503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.>
Now remember this is the actual bounce back message that the user, my client, is getting in his Outlook. What does it mean.
The other bounce back is:

 username@verizon.net on 2/2/2007 8:58 AM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            <mydomainname.com #5.5.0 smtp;550 You are not allowed to send mail:sv16pub.verizon.net>
I've spent hours on the phone with verizon. This is an inconsistant error. I can send email to this user from the administrator account. She can reply to the administrator acount. I can send an email to different user on the verizon.net network, he cannot reply.

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