Hi there!
    I just upgraded Exchange to version 2003, and also took all of my users
to outlook 2003.  Many users are still using Office 2000 for their Word,
Excel, and other bits of Office, but have Outlook 2003 installed now.  When
creating a Word document in Word 2000, one user uses the mail function from
Word, and is receiving the error that Word is unable to load the e-mail
envelope.  It says it could be caused by network connection or the Office
installation.  I have checked the network, connection, and that is not an
issue, and I have also reloaded his Office applications as well, but still
have no resolution to this issue.  Does anybody have an idea on what could be
causing this and how to fix it?  I have gone through the KB articles, and
they are kind of segregated in using Office platforms that are on the same
level only rather than a mixed mode.  Is this the only solution to this
problem?  Thanks!