[exim] Adding some lines to the body of outgoing E-Mails

Hi, all!

I need to add a footer to all outgoing E-Mails.
I use Exim 4.67.

I know, I can have problems with HTML-E-Mails, but I can't discuss with my
boss... :)

Can someone suggest me a system to add these lines to the BODY of the
E-Mails, just on the Router with dnslookup (= all E-Mails to other servers)?

Thanks a lot in advance!
Luca Bertoncello
(lucabert@???)