It works. Ask Ryan Gregg on his blog site. You don't get ribbon support, but
even VSTO addins using VSTO 2005 SE with the Outlook 2003 PIA's does work
with Outlook 2007.

--
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Absolute Beginner's Guide to Microsoft Office Outlook 2003
Reminder Manager, Extended Reminders, Attachment Options
http://www.slovaktech.com/products.htm


"SvenC" wrote in message
...
Hi,

Just reference and develop with the Outlook 2003 PIA, the code will
run with no problems in Outlook 2007.

You are walking on unsupported grounds hers.
See this Microsoft blog:
http://blogs.msdn.com/andreww/archiv...of-office.aspx

MS officially supports Outlook 2003 COM addins running on Outlook
2007. Look at the information from the Outlook team on their blogs.

I searched "site:blogs.msdn.com VSTO Outlook 2003 support 2007" and did
not get any posts which indicate that it is supported.
As I do some COM programming where I need to version correctly when
producing new releases, I know how easy it is to break something. So with
the extra layer of PIAs and VSTO (which also needs correct versioning) on
top of the COM type libraries I am a bit uneasy to believe that everything
"just works" :-)

--
SvenC