[exim] how to check sender domain against domainlist ?

Hi,

as Marc stated in my previous post, checking for the sender domain
with the "sender" verb in an ACL against a domainlist is not
possible, naturally, as I understand now. ;-)

How can I achieve this elsewise?

Again: I don't want to accept emails sent from a domain name that
I host (from an external server on the internet) to a domain name
that I host.

Michael