Comment by pepr

I have tried switching to fastmail and it was incredibly painful. In a nutshell, Microsoft/Hotmail and possibly other providers started to throw my emails to people to spam. I've missed out on important things in the physical world because of this. I've invested a lot of time trying to debug the issue. To their credit, Fastmail's customer service was excellent and they really tried to resolve the issues but in the end could not.

Also, fastmail web UI was okay but not great. I do like the new GMail UI better.