Hi @Ammar Ali Imrani ,
Welcome to our forum!
In order to further confirm the issue, it's suggested that you could log in to your web mail to check if the issue persists.
In terms of Outlook client, considering the impact of the corrupted credentials, it's suggested that you could try to remove the corrupted credentials. You can go to control pane>Credential Manager>Windows Credentials>Generic Credentials, choose you outlook accounts and click on Remove.
If the issue persists, it is suggested that you could try to create a new profile (Control Panel>Mail>Show Profiles>add) and add the account for testing to check if there are some differences.
Hope to help you!
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