Mail server for localhost

I am developing a PHP application where users to fill in a form and e-mail it back to me. To do this I need to install a mail sever that runs with localhost on Windows 7 to test my work.

What mail server do you recommend? Preferably freeware or open source.

Thanks

dunkin, welcome to the forum! Windows Live Mail is a good free option, Thunderbird is said to be too, although I've had zero experience with them. There may be others, you may need to look around. But I've had no problem with Windows Live Mail. Should you require further assistance, post back anytime.