Procmail question

[Salvador Santander Gutierrez]

Hello, list.

We have the next procmailrc:

...
! jonh at hotmail.com
...

This works, but we need to set the From field of the email the procmail will
forward to the server. For example, when the account receive a email, it
forward a email with the from field as root at ourserver.com, and we want the
from field be user at juntadeandalucia.es.

How can we get this?

Thanks very much.