The point of gmail is that they take the configuration and headache of maintaining a mail server away from you. If you're okay with running your own qmail/sendmail, then there are vastly better open source UI options than gmail. Google didn't invent email. They just run some of the world's largest mail servers as a (mostly) free service.
Really? Because I haven't found a web front-end as good. Otherwise I am happy running my own mail server.
Surely the community would expect something closer to 2014's Gmail (which is the product of tens of millions of dollars of engineer-hours, even if you skip all of the advertising-enabling gunk that an open-source clone would surely skip) before a theoretical Gmail clone got any kind of traction.
A clone that approaches "modern" Gmail is absolutely possible, of course. My original "Are you serious?" was just a bit of incredulity aimed at the person who asked "Hey, why isn't anybody on this yet? Is it hard?"
Possible? Yes. Hard? Yes.
> The idea for Gmail was pitched by Rajen Sheth during an interview with Google,[55] and went on to be developed by Paul Buchheit several years before it was announced to the public. Initially the email client was available for use only by Google employees internally. Google announced Gmail to the public on April 1, 2004.
Obviously, MS is no less evil than Google. But they exist.
If you don't want to use a tacky old Hotmail.com domain name, you can also register for an MS account at Live.com or Outlook.com - this gets you a web Outlook account which gives you email, contacts, SkyDrive (photos and docs/spreadsheets/powerpoint/etc) and calendar. And they don't have their own analogue to Plus and they've abandoned their old messaging systems, so the only "social layer" tedium is an optional integrated sidebar for Facebook/LinkedIn/Twitter.
It's actually pretty nice. I still use my gmail as my primary because there's not enough reason to switch and I like open-source Android, but MS has built a solid thing there.