Hi @Jeremy Duke
Thank you for reaching out to Microsoft Q&A.
To assist you better, I will need more information.
Can you please provide screenshots or the exact error messages via private message?
May I ask if you are using Exchange, POP or IMAP account?
If you are using Exchange, can you log in via https://outlook.office.com?
If you are using POP/IMAP, please provide your provider. Normally with another provider, you must enter the correct server names and ports, as well as using an app password to configure your email in Classic Outlook.
I look forward for your reply.
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