Most ISP mail servers support using either POP or IMAP protocols. That doesn't change the fact that it COULD have been done differently, and could still be fixed. I'm sure there are some arguments to be had over the security features of not allowing migration of OSTs and just requiring synchronization from the servers, but Really a developer (Microsoft) decision and not necessarily due to a limitation of IMAP. Leaving out the obvious fact that Microsoft wants to sell Exchange servers, the choice to make an IMAP OST be ONLY a cache of the server and not extend it beyond that is Up (with a date/time) like they can do on an Exchange mailbox or a POP3 mailbox. doesn't change the fact that users of Outlook expect to be able to have calendars in their Outlook mailboxes and to be able to do things like flagging a message for follow The fact that the IMAP protocol doesn't support calendars, etc.
The short answer here unfortunately comes across as the somewhatĬommon IT explanation that can be summarized as "It doesn't work that way because we didn't design it to work that way." Unfortunately that doesn't really address the usage case of the end user that doesn't really care whether or not the designer
I came across this topic after doing a search for "when will outlook support calendar for imap mailboxes" and since it's relatively recent, figured I'd add to the discussion.