Hi,
My Outlook.com account has just upgraded to the new version and I now see this error.
‘Be careful! This sender has failed our fraud detection checks. ‘
A solution is given in this thread.
http://answers.microsoft.com/en-us/outlook_com/forum/oemail-osend/be-careful-this-sender-has-failed-our-fraud/eda3ba65-2704-46d3-a732-633efd0db3a7
I hope this helps
Kind Regards
Malcolm