Is it possible to capture that "Send/Receive" event programmatically using VSTO?

Question

Click event of send and receive ribbon in outlook add-in any method or event to trigger any code on this event

Answer 1

Use the Application.Session.SyncObjects collection to retrieve the very first item (it is "All Accounts"), and use SyncObject.SyncStart / SyncEnd events.

See https://learn.microsoft.com/en-us/office/vba/api/outlook.syncobject