[Using Sakai] Reset password tool email without sender

[Rafael Morales Gamboa]

Hello,

We have installed the reset password tool on Sakai 2.9.0 and it is 
working fine but with one little problem: There is no sender in the message:

From: "" <>

This makes some email systems like Hotmail and Yahoo to consider it spam.
The question is how can I fix this problem? I have tried to set a From 
in the validate.passwordreset email template, but it did not work.

Regards,
Rafael