How to check incoming DKIM sigh and delete BAD?

I found something like this:

deny set acl_m1 = ${lookup dkim{${lc:${domain:$h_from:}}}}
add_header = X-Exim-DKIM-Status: ${lookup dkim{${lc:${domain:$h_from:}}}}
condition = ${if eq{$acl_m1}{bad}}
message = Bad DKIM signature

but I always get:
X-Exim-DKIM-Status: unverified

Dkim is not officially supported ... sorry.

And do we only offer official support on this forum?

Support for dkim on exim can be found at the official exim wiki.

Jeff