Hi,
the difference is in the programming technology. "Add-ins" or "Outlook
Extensions" or "Exchange Extensions" are built on the old technology like
COM, and __may__ be compatible with Microsoft Exchange Client, Outlook
97-98. "Outlook COM Add-Ins" are appers with Microsoft Outlook 2000, and its
are compatible with Outlook 2000-2003 only - they are totally based on the
COM technology, so it's more easy for developers to develop "COM add-in"
than "old add-in". But old add-ins have the access to some Outlook
interfaces which are not available for the new add-ins -- so, many new
add-ins for Outlook are still developed in "old" format.
For the user, there no difference, except you should click different buttons
to turn on/off old and new addins
Alexander Gorlach,
MAPILab Ltd.
http://www.mapilab.com/