[Mimedefang] Enumerate Email Address parts

[Brian Shallenberger]

I have sendmail 8.13.8 with mimedefang running.  I have successfully created
a simple filter to add a recipient to outbound email for a specific sender.
I am new to mimedefang and not a wiz at perl, but can pick it up quick with
some direction.

Is there a way to parse the part of the Sender's email address that precedes
the '@' character so I can build a recipient's email address?  For example:

Sender email address:  Joe at abc.com

Need to get 'Joe' and make the recipient's email address:  Joe at abc.local

The abc.com and abc.local will not change.  

The purpose is to archive email for each user to an individual user account
on our local server.  The only way I can see to do it (with my current
knowledge) would be insert an entry for each user's email address in the
mimedefang-filter.  I have done this for my email address and the
add_recipient works for me.  I just don't want to have to manage the
mimedefang-filter on a per user basis.

Thanks for any help.

Brian