Just this week I converted over to Windows mail from Thunderbird. I was having major headaches with spam in Thunderbird. The built-in filter simply just didn't cut it anymore.I read that the default Windows Vista mail had a built-in spam filter so I thought I'd give it a go. To my shock and amazement, the filter has deleted one email I wanted only (a Press Release I was bcc on) and it has only missed deleting 7 spam emails in 3 days. I had been getting about 100-150 missed spams a day. This has saved me so much time and the filter customization allows you to instantly add domain names and individual emails to your accepted or block list. It's all very clean and easy to use and it works. I am hooked.