Ive been reading on http://www.php.net/imap and I think what I want to do would work. But Im not 100% sure.

What Im wondering on is: Would it be possible to make a script where each user inputs their email server address/passwords and then the script will send the emails through the users email server ?

Basically wondering on this, as then I could prevent a user from using my email server to send spam.

Thanks