Hi KeithLwood,
In terms of the google account setting:
- In Outlook 2016/2019, navigate to File > Account Settings > Account Settings.
- Select the IMAP account and click Change (or double-click the IMAP account name)
- Enter INBOX in the Root folder path field
You will see the window below:

Put INBOX in Root Folder Path, type the "INBOX".
Yours Sincerely,
George
Hi George,
I recently upgraded my Office 2010 and my husband's Office 2016 to 365 and we're both experiencing some of the issues already mentioned in this thread (eg: "the operation cannot be performed because the message has changed" message when trying to flag a
message or send a draft email etc.
I tried your recommended steps above and after following the steps to add and then remove "INBOX', it has only reinstated some of my folders. I have no idea where the others disappeared to. Where the heck have they gone??? That's the last time I try troubleshooting
something by blindly following the guidance of a Microsoft staff member.
My husband has his own business and has had to resort to often sending emails through GMAIL as Outlook is unreliable, which is not a very good business practice as it means correspondence is scattered in different applications.
I absolutely agree with the other comments around this issue needs to be resolved, given the number of us experiencing this problem.
Regards,
Sue