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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
Using classic Outlook for Windows in business environments
I am not a computer person and also have this problem. I clicked into the Security Alert message's "View Certificate" button and saw that the certificate is issued to "outlook.com" while the security message said the internet address "outlook.office365.com" has security concern. That to me essentially is a Microsoft mess up by using Peter's credential to do business as Paul.
I think that I started to have this pop up issue around when the new certificate became effective, that was 7/25/2022.
As to some PCs/Macs don't have the issue maybe because they already have the correct security certificate installed on their computers. There is no setting in my hotmail setup for me to change in Outlook, so so far I am dealing with it by clicking ok on the box everyday.
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we are having this issue as well in our environment, will pop up randomly and nothing change in our environment. and i think only starting this summer and might be around same time when MS renewed their certificate. Hopefully someone can provide more detail what is going on soon.
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+1
Having the same issue.
Windows 10 | Office365 Outlook Client | Exchange Online
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Adding in my "US TOO!" Happens at home and in the office so don't think it's firewall as it occurs off VPN as well.
Super annoying because I do NOT want to be teaching people to click OK on certificate error. We see it on and off, it was pretty bad last week.
Hybrid exchange
CAN EAST datacenter
Only on Outlook on desktop (latest semi-annual 2202), not seeing it on Outlook for Android, and don't have iOS.
Dreading opening a case with MS....
Thumbprint: f7da87b0b58b2a2eec386ec7a60ab14d5a60a499
serial: 0f12dc8955821d6d936bcf34e50f60c5
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I have seen this happen for various customers starting last week.
I have also had it happen on my IOS phone.
Odd that MS didnt publish the issue/solution yet. Its obviously fairly wide spread.
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Following Friday morning we have not had any further occurrences with any of our clients. No issue today either.
I don't think this can be classified as anything to do with Bitdefender as we dont' use that product anywhere in our own stack but were experiencing the same issue.
@B_Toronto your support experience sounds exhausting. Hope you brought your patience! So frustrating that you gotten taken down a rabbit hole with MX records etc. This is very clearly a certificate revocation issue related to an MS cert. If there was a name mismatch I could see going down the path of a configuration issue. I really have to wonder if there is a certificate somewhere in the certificate chain of trust that was revoked, even temporarily or that some UTM products didn't like during SSL inspection and flagged as not trusted. I'm not 100% ready to blame MS on this one as I think Digicert, some root certificate, or even UTM products performing SSL inspection could be the cause.
Glad it isn't an issue today for us, but I don't like unsolved mysteries.
Chris
