Hi Lisa Jones,
Thank you for posting your question in the Microsoft Q&A forum.
Based on the error message you're receiving ("an encrypted connection to your mail server is not available"), it appears that Outlook is having difficulty using the Autodiscover service to automatically locate your mailbox server settings.
To help troubleshoot this further, I'd like to confirm a few details:
- Is your email account hosted on Exchange Online (Microsoft 365) or an on-premises Exchange Server? Since you mentioned you can access Outlook Web App successfully, I suspect it's Exchange Online, but confirming this will help narrow down the cause.
- Please run the Microsoft Remote Connectivity Analyzer test:
- Visit: https://testconnectivity.microsoft.com/tests/O365Ola/input
- Select "Outlook connectivity" test
- Run the test and review the results
This tool will test the same Autodiscover process that Outlook uses and will provide detailed diagnostics about where the connection is failing (DNS, SSL certificates, authentication, etc.).
If the test succeeds but Outlook still fails to connect, the issue is likely on your local machine:
- Firewall or Antivirus interference: Security software may be blocking Outlook from connecting. Try temporarily disabling your antivirus/firewall to test.
- Proxy settings: Check if there are any proxy configurations that might be blocking the connection.
- Outdated Outlook: Ensure your Office/Outlook installation is fully updated via Windows Update or Office Update.
If the test fails, the results will indicate exactly which step is failing, please share the results of the connectivity test and I'll help you troubleshoot this issue further.
Reference: How to Fix "Outlook Encrypted Connection Is Not Available"
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