Microsoft Office very slow with Connected Experiences enabled and without internet connection

Connected experiences do use additional Microsoft 365 services beyond SharePoint and Exchange endpoints.

Relevant facts:

• If connected experiences are turned off, related commands can be grayed out or return errors.
• Some Office functionality still works even when some connected experiences are off, including syncing a mailbox in Outlook, and Teams and Skype for Business continue to work.
• Office also uses essential services that cannot be turned off.
• “Other connected experiences” include Office add-ins, Office Scripts, Office support, online file storage such as SharePoint and OneDrive, Focused Inbox, LinkedIn contact card, link unfurling, feedback services, and Information Rights Management.
• “Connected experiences that analyze your content” include features such as PowerPoint Designer, Publish to Power BI, Publish to Microsoft Stream, Python in Excel, Read Aloud, Research, Reuse Files, and some mobile printing/export scenarios.

For the slowdown scenario, the supported troubleshooting path in the available documentation is to check network path performance rather than rely on a fixed list of Office-only URLs:

1. Test latency to Microsoft 365 endpoints.
   • Use ping outlook.office365.com.
   • Use PsPing over TCP 443, for example:
     • psping -4 outlook.office365.com:443
     • psping -4 -n 20 yourSite-my.sharepoint.com:443
   • This helps confirm whether the delay is network latency to Microsoft 365 services.
2. Capture a network trace during a slow operation.
   • Use Netmon or Wireshark.
   • Filter for DNS to identify which Microsoft 365 DNS/IPs are being contacted during the delay.
3. Check for proxy authentication delays.
   • If traffic goes through an egress proxy, repeated authentication on new TCP connections can cause slow page loads and slow switching between workloads.
   • In Netmon, add the NTLMSSP Summary and Time Delta columns to measure how long proxy authentication is taking.
   • If proxy authentication is slow, the networking team must adjust the proxy configuration.
4. Validate Microsoft 365 endpoint coverage.
   • Compare observed destinations with the published Microsoft 365 URLs and IP address ranges.

The available documentation does not provide a single complete list of all URLs used specifically by connected experiences in Office. It does show that connected experiences span multiple Microsoft 365 services, so allowing only the three listed hosts is unlikely to cover all traffic Office may need.

References:

• Connected experiences in Office
• Performance troubleshooting plan for Microsoft 365