Subscribed address in trailer

Hi,
is it possible to have ezmlm-idx put the subscribed address into the
trailer of list messages? I just want to get rid of workload generated
through people with dozens of forwards who can't unsubscribe because
they have no clue which address they are subscribed with. Can ezmlm-idx
do that out of the box (or at least has some kind of API for it) or
would I have to hack it for that?

Cheers,
Christian