[PHP] Problems with mail function

Hi wizards, I 'm trying to use mail function in PHP, but this function don't send the email , I have a server with postfix. Does somebody know how to send an email with php and postfix. Thanks in advance.

[PHP] Codigo de Captcha en PHP

Hola amigos listeros alguien conoce algun codigo libre de un captcha en php , gracias por sus comentarios.