Fix error :from option value for inquiry mailer

Because the SMTP limits, it is not allowed to prepend any host name before the mailbox of the sender.

More details about `MAIL` for **SMTP** can be found here: http://tools.ietf.org/html/rfc5321#section-4.1.1.2
And you should know why unable to prepend any hosts through: http://tools.ietf.org/html/rfc5321#appendix-C