outlook 2016 on Mac - "Mailbox already exists" error.

Sorry folks,

That theory doesnt hold. I tried archiving very early in attempting to debug this, and the issue remained. I repeated the attempt on several occasions. I had fewer than 100 emails left in my accounts and still had the problem.

I have given up on Microsoft.

The ONLY solution I could find is that I no longer use Outlook.

I have moved to Mac Mail - not something I wanted to do - something I was forced to do by Microsoft ignoring this issue. Their software was unusable.  Multiple times an hour, all mail disappears and needs to be manually reset, and then re-downloaded.

This is ANTI-productivity software. Just not good enough.

Good luck to everyone else. Hope Microsoft answers you eventually. I have left the building.

Exactly!

I suspect, as I think you said in a previous post, that it has something to do with a mismatch or corruption of some type between the client and the server.

I have two IMAP emails set up on Outlook, one of them was continuing to have the issue even after I removed most of the emails from it, so just now I removed ALL the emails from it.

I suspect without any emails to confuse it, there will be no more error messages and/or disappearance of folders...

We will see....as I start to receive emails on that account....it will be interesting to see how long it takes for the issue to appear again, and I'm hoping that's a VERY long time!

Thanks ever so much for your suggestions, Dale!!

It seems to be a syncing issue. So I guess it ca happen in any account but the bigger it is the more likely it is to have an issue between the two databases.

I deleted or archived most of the email in my IMAP accounts that I'm accessing with Outlook for Mac 2016, and so far, that seems to have fixed the issue.

What I wonder is, when will it start happening again?

i understand that the fewer emails I have accessible to Outlook, the lower the chances of the issue, but do we know what triggers it??

Thanks!

I have been doing some more investigation. It seems this is an IMAP issue that effects all Outlook accounts not just o Mac. If the IMAP gets any corruption on either end (a missing email) it will have trouble synching. It seems to recognize that something is different between the two accounts and then reloads the account to solve the issue. So keeping the size of the overall account down is the only solution. To solve mine I am archiving the last 5 years into a separate file. I can reload it if I need to for some reason. I believe this will solve the problem.