Security Certificate cannot be verified in Outlook 365

When I start up Outlook 365, I get the message "..security certificate cannot be verified. The target principal name is incorrect".

However, the certificate is valid. Anyway, I install the certificate successfully. However, the same message reappears when I start up Outlook 365 again.

Screenshots below. Any suggestions how to get rid of the message?

Answer
Answer
What type of email account do you have configured in Outlook? POP, IMAP, Outlook.com, or Microsoft Exchange?

Is the server domain the same as the email domain?

See https://www.slipstick.com/outlook/security-warn... for one solution?





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Diane Poremsky [Outlook MVP]
Outlook Resources: https://www.slipstick.com
https://www.outlook-tips.net

** I don't work for Microsoft.**
** DO NOT CALL phone numbers received in email notifications.**

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Question Info

Last updated November 24, 2020 Views 1,314 Applies to: