"No one on this site has an excuse for using GMail"... C'mon, now. I get your point, but ease it up a bit.
We can still use products built by companies. The OP has stated he's okay with "paying" using his data for the ease of use and benefits of a commercial service. It's cool you built your own! But there's a reason why GMail exists and is popular.
But yes, my setup is something I don’t expect most people to build for themselves – instead I’d hope that NAS vendors would include similar functionality, and people would start using those instead.