It's a known problem with Microsoft Mail in that MS Mail uses the RFC821
MAIL FROM: header instead of the RFC822 From: header for replies.  If you
use MS Mail, you simply have to make sure the mail <isn't> going to the
owner-listname mailbox when you send a reply to list mail.  Note that
Exchange does not have this problem.

On Fri, 1 Aug 1997 13:25:00 PDT Phelan, Howard CPT PHELANH said:
>Whenever a subscriber tries to Reply to a message, I keep getting the
>following message. :
>
>The enclosed mail file has been identified as a delivery error for list
>CALL-L because it was sent to the reserved 'owner-call-l' mailbox.
>
> ------------------------------ Message in error
> -------------------------------
>Received: from LEAV-MSLINK.ARMY.MIL by leav-emh.army.mil (IBM VM SMTP V2R2)
>   with TCP; Fri, 01 Aug 97 12:37:32 CDT
>Received: by LEAV-MSLINK.ARMY.MIL with Microsoft Mail
>        id <[log in to unmask]>; Fri, 01 Aug 97 12:45:23 PDT
>From: "Carter, William CPT CARTERW" <[log in to unmask]>
>To: owner-call-l <[log in to unmask]>
>Subject: RE: Little Test
>Date: Fri, 01 Aug 97 08:57:00 PDT
>Message-ID: <[log in to unmask]>
>Encoding: 25 TEXT
>X-Mailer: Microsoft Mail V3.0
>
>Any suggestions on what might be the cause?  I know it's something simple,
>but I cannot seem to figure it out.
>
>
>Howard Phelan
>Center for Army Lessons Learned