I was using Roudcube, but it was not powerful enough for my needs. The greatest strength of the Fastmail UI are all of the built-in keybindings. There's one for

I was using Roudcube, but it was not powerful enough for my needs. The greatest strength of the Fastmail UI are all of the built-in keybindings. There's one for almost every action, indeed, I find it friendlier than the best desktop clients I've used, let alone ones like Gmail or Roudcube.