Email rejected by Hotmail/MSN/Live/Outlook

We've had many reports of email unexpectedly being bounced by MSN email services, for example addresses, and  Microsoft are "looking into this issue along with the Escalations Team", but they all seem to be on holiday.  As a result we had to work around their block, but your GreenNet email to Hotmail users may still appear in the recipient's "Junk folder."