Connection to outgoing server smtp mail.outlook.com failed

The error "connection to outgoing server smtp mail.outlook.com failed" typically occurs when your email client or application is unable to establish a connection to the Outlook.com SMTP server (smtp.mail.outlook.com) to send emails.

Here are some common causes and solutions to help you resolve this issue:

  1. Check your internet connection: Ensure that your internet connection is stable and working properly. Restart your router or modem if necessary.
  2. Verify your SMTP settings: Double-check your SMTP settings in your email client or application. Make sure you're using the correct server name (smtp.mail.outlook.com), port number (587 or 25), and authentication method (OAuth or username/password).
  3. Check your account settings: Ensure that your Outlook.com account is set up correctly in your email client or application. Verify that your username and password are correct, and that you're using the correct account type (e.g., POP3 or IMAP).
  4. Firewall or antivirus software issues: Firewalls or antivirus software may be blocking the connection to the SMTP server. Try temporarily disabling these programs or configuring them to allow outgoing connections to smtp.mail.outlook.com.
  5. Port blocking: Some networks or ISPs may block certain ports, including port 587 or 25, which are commonly used for SMTP connections. Contact your network administrator or ISP to see if they can unblock these ports.
  6. Outlook.com server issues: Occasionally, Outlook.com may experience server issues that prevent connections. Try waiting for a few minutes and then retrying the connection.
  7. Authentication issues: Ensure that your authentication method is correct. If you're using OAuth, make sure you've authorized your application or client to access your Outlook.com account.
  8. Email client or application issues: Try using a different email client or application to see if the issue is specific to the one you're using.

To troubleshoot further, you can try the following:

If none of these solutions work, you may want to contact your email client or application support team for further assistance.