Hi @CWT ,
The following picture shows the URLs, IP address ranges and ports that are required for Office 365 connectivity.
Are the Exchange Online & Skype for Business Online and Microsoft Teams URLs provided in that link all trying to hit our EWS virtual directory?
Exchange Web Services (EWS Endpoints):
Yes, for calendar app support and Teams outlook Add-in for Mac, Exchange Web Service URLs must be configured as SPNs in
Tenant Azure AD for the Exchange Service Principal. For more details about steps about it, you can refer to:
For more details about troubleshooting Teams calendar issue, you can learn it from:
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