[Exim] Exim Configuration Problem

Dear all,

We was using Exim MTA in a IMAP (webmail) configuration and we are facing a
little problem.

When I send a message with a wrong address the Fail Delivery message
returns only to my Webmaster e-mail, and he have to re-direct it to correct
user.

I change the Return_path variable but this don't fix the problem.

Please, anybody can help me ? Do have a idea to solve this problem ?

Thanks and regards,

Cesar Silva
FYT Group - Brazil