Exchange account does not receive out of office replies

I have a client that is using Outlook 2010, Exchange 2008 (SBS 2008).
The issue they are having is that none of them in the office receive out of office messages from one particular domain (*@hp.com) It has been confirmed that hp.com have their out of office set to go to both internal and external addresses.
My client receives out of offices from other mail accounts.

really struggling with this, can anyone shed any light?
 
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