Hi @지현 정 ,
Welcome to our forum!
Please kindly understand that:
Currently, POP and on-premises Exchange accounts aren't supported. When attempting to add an account that isn't supported, an error message is displayed: We couldn’t reach the email server. Please try again.
If you need to configure your account as POP, i'm afraid that you need to switch to Legacy Outlook.
More information: Accounts in the new Outlook for Windows.
Hope to help you!
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