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What Ports and Whitelists are Needed in a Network to Run the Outlook Desktop Sync?


  • Outlook Calendar/Contact/Task sync network configuration


  • Outlook Desktop Sync
  • Microsoft Outlook 
  • Windows

Additional Information:

When a local network has highly restrictive permissions you may need to whitelist and open certain ports on your network.


  • Open port 443 or 80
  • Whitelist the companionlink.exe process
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