I am looking for an Outlook Event-Driven Office Web Add-In for Visual Studio with a .sln file. Something like an add-in with an event that triggers on OnNewMessageCompose and creates a subject line or triggers on OnMessageSend and encrypts any attachments you might have. I do not need to have an associated task pane, but I would not complain if the example had one as well.
I have found multiple examples of Outlook Event-Driven Office Web Add-Ins, but I have not been able to get any of them to work in Visual Studio, which is where my limited expertise lies. What I have found are pieces of code like this one or complete solutions like this one developed in other compilers such as Visual Studio Code, but again not incorporated into Visual Studio. I have also tried to get things to work in Visual Studio Code directly but failed miserably at this as well.
My bad for not being more expert, I know. In my defense, this is my first try at a Web Add-In and my experience is really with Visual Studio.