Forcing exim to use a single address when sending email

Question

My ISP requires my sender envelope header, and from: header to be a specific address. How do I configure exim to force all email to have this address when relaying?

Answer 1

Assuming you have fairly standard routers/transports. Simply modify the transport that is used for outbound mail to perform address rewriting:

remote_smtp:
  driver = smtp
  headers_rewrite = *@+local_domains newaddress@example.com fsr
  return_path = newaddress@example.com

The first rule will handle From/Sender/Reply-To and the second Return-Path.

You can replace +local_domains with a wildcard if you really wish.