Strange mail bouncebacks

  • Thread starter SeanTranquil
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Hi All,

hope someone can shed some light on this as it is driving me nuts.

I have a single user in our exchange 2010 organization that is unable to receive mail from a single external user.

I have had the user send me a transcript of her NDR and she is receiving

<tt>>>> DATA</tt>
<tt><<< 554 5.1.0 Sender denied</tt>
<tt>554 5.0.0 Service unavailable</tt>

<tt>I have checked all of the filters on the transport server and can't find a reason why she should be being bounced. </tt>

<tt>I have even added her to bypassed senders in the contentfilter config in the hopes it might be something odd with anti-spam, but that does not appear to be the case. </tt>

<tt>Whilst the user sending the mail is from the domain, we do not appear to be experiencing this issue with other users sending from</tt>

<tt>I'm stumped.... Any clues please??</tt>

Sean Watson

Bellaard [MVP]

Dear Sean

It's still looks like its anti-spam. Ask de reciving user to chekc his block senders. He can do this from outlook.

Martijn B.

Elvis Wei

Hi Sean,

Please double-check your anti-spam settings, both in server side and client side. Please also check your SMTP log to see if you could find some clues there.




Thanks a lot guys, it was the blocked senders on the Outlook client that was causing the issue.

Had to restart the exchange server before it picked up the changes, but all seems to be ok now.

Thanks for the input.

Sean Watson
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