Outlook: The Message Could Not Be Sent - An Error Has Occurred

Email | Updated 2026
Quick Answer

This generic send error usually means your outgoing (SMTP) server settings are incorrect. Set the outgoing server to mail.yourdomain.com, port 465 with SSL, and enable SMTP authentication using your full email address and password.

For complete Outlook troubleshooting steps and all error codes, see our full guide:

Common Outlook Email Errors

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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