Re: [exim] rewrite From: with MAIL FROM:

I don't want to setup mailing lists, if I did I would rather like to
deactivate such rewriting then because such usage for exim is much more
rare.
Additional headers are insufficient as they dont stop abusers. Abusers still
can and want to use your mailsystem to relay their email (with custom
from:), but using authitenced smtp users (which they can aquire when signing
up for free service)