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Outlook Can't Connect Because of a Certificate Error

Applies to: Office 365 for professionals and small businesses, Office 365 for enterprises, Microsoft Exchange, Live@edu

If the following error message appears when you try to connect to your e-mail account using Outlook, there's probably a problem with your security certificate.

Error message

There is a problem with the proxy server's security certificate.

The name on the security certificate is invalid or does not match the name of the target site <domain URL>

Outlook is unable to connect to the proxy server (Error Code 0)

You may be able to resolve this security certificate error by repairing your Outlook profile. For information about how to repair your Outlook profile, see Repair the Connection to Your Account in Outlook.

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