Receiver mail communication channel with status "not initialized"

Hello dear XI fans 😊

I'm playing around with the mail adapter of my PI 7.0 SP11. Since this is my first try, I've given dumb values for c.c. fields. When I do activate it, I see the "not initialized" status in RWB. I don't think it's because of configuration values because I have set them according to many blogs/guides. It looks like a component configuration error. Any solutions?

I have reviewed following already:

XI/PI Mail Adapter FAQ

SAP Library - Receiver Adapter Configuration

And a dozen of other SAP notes...

Thanks! (BTW: R.P. on the way!)