RequestedDeletion: there are many posts where I talk about zarafa..
zarafa is a great product, its web interface is better than M$ one, people love it
but zarafa is an exchange replacement.. i.e. it's designed to work with/for outlook (and just this should be enough to say "NEEEEEXT", IMO)
it's an exchange replacement and so you have email stored in a big mysql database.. it doesn't matter if attachments are on filesystem, every email is stored into a big blob..
even the error messages are M$ style..
in any case, migrating from zarafa to something else (and "something else" doesn't apply to anything running on windows) must be done via escamotages.. i.e. imapsync, for example
many other groupware suites (SOGo, Egw ecc) are only an "interface".. mails are stored in plain, well known, universal maildir format.. and there's no need of "proprietary" imap/pop/smtp services running.. SOGo uses standard imap and smtp..
you can install sogo (no need to disable webmail, no need to touch anything), use it, try it, remove it, without any issue.. everything is still there..
in any case, as I said (too) many times, this is my opinion.. if you want to use imap (let's say you want to/must use thunderbird or evolution or anything on your android), you don't need zarafa.. and maybe you don't need SOGo too.. SME is enough
finally, even if windows will remain unbeatable on pcs, we can still make this world a better place simply stopping using outlook as a mail client (and everything it can/should not do)
using SOGo, if you tomorrow move to OSX or linux, you'll have everything here, in the same way, same UI, same features..