Just thought I would share Mail-in-a-Box . It makes it real easy to set up a email server with ownCloud for those who are trying to seperate from the goog.
I set it up yesterday on a DO droplet and it’s doing quite well. I have email, contacts, calendar and my own cloud filesync going now…pretty nice.
Was just looking at doing exactly this yesterday. Keep us posted on how it goes and if you keep using it. 
So far it’s working like a charm. I haven’t had any issues yet…I’m not a big fan of roundcube. But I believe they are toying with mailpile…and now that ownCloud is getting ready to have a mail client add on that could be great!
Also Mailpile looks really interesting, I’ve been intending to try it out, but I have Postfix/Dovecot/Roundcube running just nicely, so I’m not sure what I would gain for now.
I believe they have a beta for Mail-in-a-Box that replaces Roundcube with Mailpile. Haven’t tried it though…I’m waiting for mailpile to go stable and i’ll probably switch.