Outlook The Security Certificate Was Issued By A Company You Have Not Chosen To Trust [hot] «2025»

Microsoft designed this error message poorly. It sounds like a paranoid accusation ("You have not chosen to trust"), but in reality, it is a factual statement. It is Outlook saying, "I am missing a piece of the puzzle; I cannot verify the bouncer's ID."

If you are in a hurry and know the server is safe (e.g., your IT team confirmed they use a self-signed cert), you can click or "Continue" on the pop-up. However, you will see the prompt again every time you restart Outlook or after a few hours. Microsoft designed this error message poorly

IT must push the proxy’s root certificate via GPO or MDM. If you see this error on a personal device on a corporate guest network, do not bypass it. You are asking for your personal credentials to be logged by the company firewall. However, you will see the prompt again every