Hi @Ed ,
Let's make this issue more clear, you have an O365 email account and it can work fine on the web mail. But you encountered issues when using this email account in your Outlook desktop client, right?
If so, have you successfully added this email account to your Outlook? To better understand and solve your issue, would you mind providing screenshots of your errors for further research? (Notice: Please hide your personal information in the screenshot for security.)
If you have already added this email account to your Outlook and encountered sync issues, in most cases, creating and using a new Outlook profile via Control Panel > Mail > Show profile and re-adding your email account should be able to help fix your issue.
If you got troubles when adding your email account to Outlook client, please show me which step you were stuck at so that I could find the key of your issue.
Any update, please feel free to post back.
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