I've had a string of people lately complaining about problems with Microsoft "in the cloud" mail products and/or having problems sending messages to me from this service.
Someone trying to email me who uses one of their services somehow (not sure exactly how he's set up but there's a Microsoft IP of some kind in the set up) is having problems emailing me. I've checked all the IPs he's using and his mail server IP and they're not blocked.
A girlfriend of a friend was complaining that she was having problems with her Microsoft mail. Not sure the details there.
Then, strangely a customer complained that he could not get messages from someone. When a message finally did get through it came from a Microsoft mail product - from an IP that should have been blocked by Postini. The Microsoft IP was ok but it originated from a blocked IP.
Not sure what is going on here exactly, just been hearing about and having problems myself with mail related to Microsoft's online mail services in various ways.