We are migrating to a new server, and need a mail filter written for Exim.
We use Google Apps for email, but use our [url removed, login to view] server as the outgoing relay. Google insists on including the "Sender: name@[url removed, login to view]" header, which creates the dreaded "On Behalf Of Display" in mail clients. It's not required by RFC, and we need the header removed on all outgoing mail.
On our current server, we already have this working for SendMail -- we had someone code a Milter. Now that we'll be using Exim, we need an identical mail filter written for Exim that will remove this header from all outgoing email.
It's critical that all steps are documented, so that we can replicate them in an emergency.