Hotmail and Outlook's anti-spam measures are usually sound, and i've come to rely on them. It seems the filters, or something, broke and users were suddenly receiving lots of messages they wouldn't normally see.

It seems it's all back to what it was, but we're none the wiser as to what caused the problem as Microsoft is remaining tight lipped.

"Some users may be receiving excessive spam mail," a service page update stated.

The company later said it had managed to put in place two sets of fixes to protect users' inboxes and its own infrastructure. Outlook and Hotmail Spam Filters Break, Resulting Spam For Users [bbc.co.uk]