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  • Description
  • Policy
  • Licensing Considerations
  • Set Up Instructions
  • End-User Impact
  • PowerShell Scripts
  • Videos
  1. Security
  2. Exchange

Calendar and Contact Sharing SHALL Be Restricted

PreviousSimple Mail Transfer Protocol Authentication SHALL Be DisabledNextExternal Sender Warnings SHALL Be Implemented

Last updated 1 year ago

Description

Exchange Online allows the creation of sharing polices that ease default restrictions on contact and calendar details sharing. These policies should only be enabled with caution and must comply with the following policies.

Policy

  • Contact folders SHALL NOT be shared with all domains, although they MAY be shared with specific domains.

  • Calendar details SHALL NOT be shared with all domains, although they MAY be shared with specific domains

Licensing Considerations

This setting can be configured in any Microsoft tenant.

Set Up Instructions

To restrict sharing with all domains:

  1. Sign in to the Exchange admin center.

  2. Under Organization, select Sharing.

  3. Under Individual Sharing, for all existing policies, ensure that for all sharing rules, Sharing with all domains is not selected.

End-User Impact

Level: Low

With this setting in place, users will not be able to share calendar or contacts to any external domains unless they are whitelisted. A formal request process should be put into place and evaluated when a user needs to share their calendar details.

Tips

None Currently

PowerShell Scripts

Videos

None Currently

Free/Busy Sharing Settings:

Free/Busy Sharing Settings (Multi-Tenant):

🔐
Sharing policies in Exchange Online | Microsoft Learn
Sharing in Exchange Online | Microsoft Learn
https://github.com/msp4msps/Security/blob/master/Free_Busy%20Calendar%20Settings-Single%20Tenant.ps1
https://github.com/msp4msps/Security/blob/master/Free_Busy%20Calendar%20Settings%20Multitenant.ps1