We’ve posted quite a bit recently about the work we’re doing to prevent spam on Windows Live (Just say no to bogus Messenger invitations
, Preventing spam and phishing using e-mail authentication
, Spam, phishing, and other annoyances
, and Fighting the war on spam
In our fight against spam, we sometimes have to make hard choices, and we had to make one this week. We discovered that spammers were using Hotmail’s automatic vacation reply feature to send spam from their Hotmail accounts.
We decided to temporarily shut off the feature in order to shut down the spam. Of course, we know some of you like and use automatic  vacation replies to let people know when you can’t respond to e-mail for a while, and we’ll turn this feature back on as soon as we’ve worked out the best way to prevent it from being misused by spammers.
I apologize to all of you who use this feature for any inconvenience we’ve caused.
Lead Program Manager, Windows Live Hotmail