WordPress Error Message : Possible reason: your host may have disabled the mail() function…
By default WordPress uses Mail() component to send out emails. But if your host has secure SMTP eMail authentication then Mail() will not and you may see this error.
Solution for this problem is using wp-mail-smtp plugin. Its a very very simple plugin, which accepts smtp host, username & pwd and sends out email via SMTP host.
This plugin can be downloaded from here.