troubleshooting Question

Security alert in Outlook for office 365 Certificate

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ajdratch asked on
Microsoft OfficeExchangeMicrosoft 365
11 Comments1 Solution5147 ViewsLast Modified:
I have a client that moved to Office 365 from on-premise Exchange 2010. They are using AD Sync so the old Exchange server is still online. When they open Outlook, they get a security alert for Outlook.office365.com - the security certificate for this site had been revoked. When I click to view details it shows it is issued by digicert and is valid until 8/1/2020.

This only happens when opening Outlook inside the network. laptops get this message inside the network but not outside.

Autodiscover is working properly. On the on-premise server I run Get-ClientAccessServer |select AutoDiscoverServiceInternalUri and it shows https://autodiscover.outlook.com/Autodiscover/Autodiscover.xml. I can ping autodiscover.domain.com and it returns Office 365 autodiscover name

How do I stop that security alert from coming up
ASKER CERTIFIED SOLUTION
Brian Murphy
Senior Information Technology Consultant
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