NC Webmail UI is poorly designed: compose window is just a small box on the center of the screen, there’s no way to have the markup tools permanently show up;
NC Webmail UI is broken: if you select a bunch of text and turn it into a bullet list, the bullets won’t even show up on NC, other e-mail clients will see them tho;
Integration/SSO with IMAP is cumbersome: not well documented, default configuration doesn’t even handle a simple “login with the email email and password as the IMAP account” type of setup that is commonly expected;
WebUI is slow and fails often: if you open the browser console you’ll find lots of warnings and errors.
I do have a lot of complaints related to mail but if NC is any kind of useful replacement for MS365 / Google Workplace a decently working webmail is the bare minimum. RoundCube is WAY better than what NC is currently offering.
alado