It will be easier to build a new email spec that&#x27;s more feasible&#x2F;modern with security built in mind than it is to build a sustainable email client that tries to comply with various email services (GMail is the worst offender for not being consistent with IMAP spec).<p>Mailmate is my fav OS X client that focues more on power user features but it has a boring classic interface which doesn&#x27;t bother me at all. Despite having integration support with SMIME&#x2F;PGP, Markdown reply, powerful search features, and so on that makes me productive, the only thing I hear when I recommend this to other people is that its UI is ugly. :|