Anonymous Emailing API PHP/Objective-C

I just wanted to know if there w开发者_JS百科as an api for sending an email with the email address that the email is going to be sent by, set by the user. I would like to do this either via php or objective-c, or any other platform.

<?php
    mail('to@somewhere.com', 'subject', 'message', 'From: from@somewhere.com');
?>

http://php.net/manual/en/function.mail.php

I would say you need to create a contact form using HTML and PHP. There are tons of good tutorials for doing this. And yes, you can send anonymous mails with this or with a specific adress...