attachement loss from postfix & sendmail

Hi,

I have inherited an elaborate mailing system. One of my intermediate mail server has the following components:, Antivirus, postfix and sendmail.

Antivirus listens on post 25, scan the incoming mail for virusus and hand it over to postfix. Postfix does some header-rewriting and hand it over to sendmail (non-daemon mode). In the transition from postfix to sendmail, the attachement is lost in some cases (particularly those coming from postfix and exim).

Would be grateful, if some one can shed some light on this?