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Exchange 2010, Error 451.4.4.0 Primary Target IP Address responded with 556.5.7.1

Posted on 2013-12-10
Medium Priority
Last Modified: 2014-01-07

I have a client running SBS2011 with exchange 2010.

When they send to one particular email address the message stay in the queue viewer with the following error "451.4.4.0 Primary Target IP Address responded with "556.5.7.1 Dynamic IP Addresses are blocked. Please contact your email provider"

I have search the web but cannot find this exact error. Can anyone advise what this error is caused by.

Thanks and kind rergards,
Question by:VitalNetworkSolutions
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Expert Comment

ID: 39710547
I would start with you ISP or check with the IT department from a blocked email, contact them on another account for example gmail and explain the situation. My understanding is some IT guys, meaning how they configured their servers and some ISP block dynamic ip's for spamming reasons.

What does http://mxtoolbox.com tell you?

Expert Comment

ID: 39710745
you need to send via your ISP mail server, use the 'internet email' smart host wizard in the network tab of sbs manager.

Accepted Solution

VitalNetworkSolutions earned 0 total points
ID: 39753347

I eventually found out the issue was at the recipient's end.


Author Closing Comment

ID: 39761672

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