Hi Marc,
I have recently been working/testing with exchange 2016 and started thinking if I should even migrate to this platform. I assume more people here have experience with exchange and this idea.
I was an Exchange admin for years and even had an Exchange server at home for about 20 years - just for fun and for testing purposes. Three months ago I migrated to dovecot and baikal - and dropped Exchange completely. This worked flawless, so *I* don't miss Exchange at all.
But:
You can't compare dovecot with Exchange, because dovecot is a mail server, Exchange is a groupware server. This is why I added a baikal server to my infrastructure. Baikal is a Cal- and CardDAV server, that can replace the calendar und contact parts of Exchange. Nevertheless you loose many features of an Exchange server after migrating to such a setup, so if your users got used to these feature, it wouldn't be possible to drop Exchange. It is only feasable for small environments with few people or in a new environment, where nobody has used an Exchange Server until now. IMHO. This was not your question, it is meant as background information, if you wouldn't already know that.
For your environment I can't tell if it is possible to migrate to Exchange, because you didn't write, if you already have an Active Directory in place, which is necessary for Exchange on premise. If you want to use Microsoft's Azure AD and the Exchange cloud services on top, you have to migrate your users to Azure AD. In any case you need an Active Directory for Exchange server.
I was wondering if this is possible with a dovecot setup
- public folder can be implemented with a public mailbox?
Yes, but public folders in Exchange are dying for years. They still exist, but are only supported so so. Public mailboxes in dovecot are supported full fledged.
- authorize users via groups access to mailboxes/folders of the public folder/mailbox. I think I saw ACL's with dovecot, does this compare to 'folder permissions'
Not really, but I'm not an expert for permissions on public mailboxes.
- is it possible with sieve to apply a rule on any mailbox/folder? Thus if I 'drag' a message to a folder, the sieve rule is activated?
You can configure a folder to act on incoming mail in the folder properties. I never tested, though, if "incoming" also applies when copying to a folder.
Bye. Michael.
Michael Hirmke