Maybe have a look at mailinabox [1] on your own server, that would actually come close to a proper comparision? Have been running it under Docker for half a year or so and had no real problems so far. Setup is easy enough in comparision with a complete DIY server. Community is fairly active as well.
Re:Open-source alternatives to GMail
by ChrisArgyle on Thursday September 10, 2015 @11:30AM
(#10198639)
Same experience here running a client's email server (Postfix, Dovecot, SpamAssassin, ClamAV) for 2 years.
Spam filtering techniques (and subsequent techniques for circumventing them) are constantly changing.
On this list, I believe at only Zimbra provides all of these options, but the article really only looks at the client.
Having run my own email server for about 10 years (1996-2006), I eventually gave up due to the huge amount of work it took to stay secure, current with email server "policy" and deal with spam.
I have always either run my own server or paid for the service. I have never used Gmail beyond a use as a testing and backup email account.