Thanks for the input which actually got me to solve the problem - at least in part, the additional plugin (which I had) suddenly stopped working one day. When I approached Mailbutler support, they told me it was their problem so I didn't even try to solve... today I played with the configuration and it's working again... This kind of integration with important platforms such as Mail for Mac could be an integration Evernote could offer directly IMO - I find the integration with Mail priceless, an incredible added value