Very Confusing PST/OST message

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Senior Member
Outlook version
Outlook 2016 64 bit
Email Account
I want to be my primary mail source. Please see the clip at the bottom of the message. In trying to set the "rr" data file as default, the message shown below popped up. I am completely confused about my next move. My only purpose in wanting a connection to is to have it sync my "rr" messages with my phone.
I'm also afraid to delete any data files for fear of losing my contacts and calendar which seem to be in the custody of
What might be the logical steps to extract myself from this tangle?


Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Hmmm. it should work with current versions. Do you have all updates installed?

It was broken in past versions and the steps to make it work are here - Set Another Data File as Default When Using an Exchange Account - but accounts won't let you disable cached mode now, so those steps probably won't work for you.

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Scratch that - it looks like it is still broken for imap accounts, or was fixed and broken in an update... but the steps on that page are working with accounts.

Keep in mind that when am imap data file is set as default, the folder labeled ' this computer only' will not sync to the server or be backed up - you will lose the contents if anything happens to the pst file.

The default data file only determines where calendar and contacts are stored - it can be different from the default email account and you can change the order of the accounts in the folder pane (drag up or down) and set the IMAP Inbox to open when you open outlook.
Choose the Folder Outlook Starts Up In
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