Mail en Freeprohost

Para todos aquellos que usen este hosting en una cuenta free tienen el peque�o inconveniente que la funcion mail() esta desactivada.
En Help Center del panel de usuario se explica los motivos de que este desactivada:

You can be having trouble sending e-mail using Formmail script, because of the following reasons:
1. You have entered an e-mail address which is not hosted on our servers. We require the one of either the ‘FROM:’ e-mail address or the ‘TO:’ e-mail address to be hosted on our servers. Only if one of them is hosted on our servers, you will be able to send e-mail successfully.
2. You are using wrong header information. You must always provide the text From:, the name of the sender and an e-mail address. Without one of these three parameters, the formmail script will not work properly and will not deliver e-mail to your mailbox. You can find out more information here: http://www.php.net/manual/en/function.mail.php

Existen otras alternativas para poder enviar emails sin usar mail() es utilizar las clases PHPMailer y SMTP, el plugin wpPHPMailer para WP creado por Scott Reilly hace uso de estas clases,
En Programacion en Castellano teneis una explicacion de uso de la clase PHPMailer para profundizar.