[Exim] forwarded emails not arriving

Hi,

just a quick question:
Can it happen, that the email system (exim) works just fine, but only
forwarders don't work (arrive in the inbox)?
The problem is, that those forwarded emails don't even appear in the log
files. So it seeems as if the remote server didn't even try to connect
to the receiving one.
I would say the problem has to be on the remote server, but several
users from different servers reported the same problem, where emails
arrive in a matter of seconds, but forwarded ones, simply never hit the
inbox & not even appear in the logs!

Could the error really be somewhere on my side?

Thanks,

Duncan