How can I backup Outlook for Mac 2016 on my mac? I am in need to clean up my outlook for mac 2016 and looking forward to an organized mailbox. But before that, I need to backup all my email database from outlook mac so that I don't lose any emails. The Outlook for mac export is taking a lot of time to export the mailboxes as they are quite large in number. Is there any other way around to backup the outlook for mac 2016?
Let the export complete. The internal storage of mails in Outlook 2016 for Mac is a cached version for all imap / google accounts that changes internally from version to version. 

The export yields a far more standard and stable data dump which serves the purpose of being importable at a later date. 

If you have local folders - on my Mac then things are slightly more complicated. Perhaps that's part of the slower export?