I am creating a dot net application that has to support outlook 98, outlook 2003 and outlook 2007. I can add a reference to the c# project for outlook 98 and most things work across the versions. However I am try to hook up the mailItem.Send event and am having issues as outlook 98 event/delegate has different signatures than outlook 2003. To cope with this I have created an overloaded function one for each signature. This approach has not worked and the event is only caught under outlook 98. No errors are generated. Is there a way around this or a better way to support multiple versions of outlook in c#? I hope this is the right place to post this message. All ideas welcome. Thanks