security certificate revoked - outlook.office365.com

John Rovel Kalaw 6 Reputation points
2022-07-27T04:28:49.213+00:00

Hi

The pictures below started popping up on our PCs. and the PC was using not part of any domain. I tried to follow the link below but the IE was inaccessible. https://answers.microsoft.com/en-us/outlook_com/forum/all/outlookoffice365com-security-certificate-has-been/743bdb2b-06ce-4206-923e-bdb7041528bd

225096-image.png

Outlook | Windows | Classic Outlook for Windows | For business
Windows for business | Windows Server | Devices and deployment | Configure application groups

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  1. Cameron R 6 Reputation points
    2022-10-28T19:55:05.29+00:00

    I own an IT company and several of my customers are reporting this to me across the board. Some running AD sync and some not. Not all of the mailboxes for each domain experience this, only some. This has been happening since yesterday. There is no way this is related to anything other than a Microsoft issue itself. Does Microsoft reply to this or see this stuff or I wonder how many people have reported this by now.

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  2. Mike C 1 Reputation point
    2022-10-28T15:56:47.98+00:00

    Same issue for many of our users using Outlook client and iOS so far. It is impacting both intranet and internet remote workers so is not Firewall specific.

    Don't trust Microsoft to get certificates 100% right 100% of the time - by preventing 10% of users from connecting randomly they increase capacity by 10%!

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  3. Chris Robb 21 Reputation points
    2022-10-28T14:53:46.33+00:00

    We're hearing reports of this for on-premise users of M365 starting this morning. we use Fortinet Fortigate firewalls, wondering if this is a certificate inspection issue with an outdated or incorrect CRL list.

    Chris

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  4. -Asli 11 Reputation points
    2022-10-28T14:00:36.043+00:00

    We are having the same issue on a few systems in our environment as well.

    The security certificate revoked error pop-up occurs at random times for on-premises users and remote VPN users (VPN is configured to split-tunnel mode).

    As per Microsoft support, we updated the Outlook client to version 2202 and created new outlook profiles, but the pop-up still occurs. Time is also synced.

    Yesterday the error started popping up on my machine several times as well.

    So far, we can see this error only for SSL certificate from Digicert Cloud Services CA-1 with serial number: 0f12dc8955821d6d936bcf34e50f60c5 that is currently used by outlook.office365.com

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  5. Bryson Nichols 1 Reputation point
    2022-10-28T14:00:07.847+00:00

    We are also getting this alert now with PCs using Outlook Desktop on our local network.

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