Mail is not sent by php function mail()
I joined to a big web hosting provider in Brazil and my wordpress/classipress instance it wasn`t sending any mails.
Searching for a solution I found the reason why it wasn`t working. It`s related to Postfix and sending mails matching international rule RFC 822.
Follow a link in brazilian portuguese that explains how to deal with this requirement.
Shouldn`t wordpress make an effort to match this international rule?