Outlook setup security certificate alert

Our small company is moving our email server to an online Exchange server with the office365 business subscription. Currently, we have been using a linux server for our email server accessed via Outlook for all employees.

I have had no trouble setting up with the linux server. However, when we try to connect Outlook to the new office365 account, we get this error that prevents the setup:
Popup error

I must note that we do NOT have any issue setting Outlook up on a computer that is NOT joined to our company domain. We ONLY receive this error when trying to configure Outlook on a domain joined computer.

I’ve tried clicking “view certificate” to install the certificate but this does not seem to do anything.

I also deleted the certificate key in the local registry as per an online forum I searched but again to no avail.

Any ideas? Thank you!


The name from the ssl certificate do not match the real hostname which is used here. With the infos you provided I would say this is a selfsigned ssl certificate.

Source : Link , Question Author : Community , Answer Author : BastianW

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