Outlook: Error Message: An Unknown Error Has Occurred

Email | Updated 2026
Correct Email Settings

Most Outlook errors are caused by incorrect server settings. Use these values:

  • Incoming/Outgoing Server - mail.yourdomain.com
  • POP3 Port - 995 (SSL) or IMAP Port - 993 (SSL)
  • SMTP Port - 465 (SSL)
  • Username - your full email address
  • Authentication - enabled for outgoing, SPA disabled

For step-by-step setup: How to Set Up Email in Microsoft Outlook

This article has been consolidated into our Common Outlook Email Errors guide for easier reference.

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