I've posted this in the Dutch section first but I didn't get a response so I'll try it in the English section.
One of your clients is using google apps for a few months now.
Everything is working okay  expect that we have allot of problems with mails sent from hotmail.
These mails are sent back to the sender without any error what so ever.

They only get (for example).

This is an automatically generated Delivery Status Notification.
 
Delivery to the following recipients failed.
 
       *** Email address is removed for privacy ***

I've opened about 5 calls with google over the last couple of months and sofar without any sollution at all.
During this call google stated that they can't find the error at their end as it's going wrong at outlook/hotmails ends.

I really hope someone can help me with this problem or if someone knows how to contact the outlook.com support.
Because I now get about 5 questions per day why people sending mails from hotmail are getting them back.

Thanks you in advance.

Eric