Off the top of my head - offline support, PGP support, multi-account support, decent mail-list&#x2F;threading support, separation of client from service provider..<p>I&#x27;m actually quite a fan of the gmail interface; it is one of the most usable webmail experiences in my opinion (I use google apps both at work and for personal use). For day-long usage, I&#x27;d rather stick with mutt&#x2F;vim.