That's funny, because every time I use an MUA other than mutt I'm frustrated by how janky it feels to process email with a mouse. :)

The little-used commands can be found by pressing "?" in any mode. You get a nice list including any custom macros you've set up (I don't use many, but a few are essential). It's far simpler than clicking all over menus and dropdowns and hovering inscrutable icons...