What can cause SMTP authentication errors?

SMTP authentication errors can occur for several reasons. The most common cause is incorrect email client settings, such as using the wrong username, password, or server settings. Ensure that your email client is configured to use SMTP authentication and that you are using the correct port numbers, typically 587 or 465 for SSL connections. Additionally, check your firewall or antivirus settings, as they may block the SMTP port. If you’ve verified all settings and still experience issues, consider contacting your hosting provider for further assistance.

For more information on Troubleshooting Email Issues in cPanel, check out our detailed tutorial Troubleshooting Common Email Issues in cPanel .