Hi Dicky!
> Although exim bt works fine and correctly identifies where the mail should
> go to when actually sending a mail the unknown router for some reason gets
> skipped and bounces the mail.
If you have no_verify set on the router, it will be skipped during
recipient verification. Either remove the no_verify, or disable
recipient verification for local domains (won't do much good anyway,
if mail to any local part is willingly accepted).