[Exim] queue Problem: no envelope from address

Hello,

when a mail have spent too long in queue it is send automaticly back to
sender.
But why is there than no sender address when using $sender_address?
In the header of the mail there is From:MAiler-Daemon@???.

When looking at mailq there is also no.

71m 4.5k 12345-ID-000122345-00 <> *** frozen ***
        test@???

Is there any posibility to add one?

Steffen Herold