the contact form of the xzero classifieds site needs some changes

the contact form of the xzero classifieds site needs some changes due to the authentication Changes at Yahoo! any client who tried to contact with ad poster via contact form using @[login to view URL] address, but not mailing form their yahoo account is considered a spam according to the yahoo, so the email never delivered to ad poster. So i need to create some changes on contact form like what i see post.php. No problems when u post ad using @[login to view URL], because the server replies from my @mywebsite.com. So basically, if your From email address doesn’t match the sender address from the mail server, ISPs may think the email is fraudulent, or spam, and block it from their system.