Email sending failed – 530 Authentication Required

Learn what causes the 530 Authentication Required error and why it occurs when sending emails. You’ll also discover how to authenticate your email properly so your messages send successfully. 

Problem 

Users may encounter the 530 Authentication Required error when they attempt to send an email without authenticating with the mail server. In this case, the message remains in the Outbox, or the error is recorded in the mail server logs. This error can appear in several places, including: 

• Email clients such as Microsoft Outlook, Mozilla Thunderbird, or Apple Mail when sending a message.  
• Webmail platforms like Roundcube after clicking Send.  
• Mail server logs or bounce messages in hosting panels such as cPanel & WHM or Plesk.  

Common error messages:

530 Authentication Required

530 5.7.0 Authentication required

530 SMTP authentication is required

530 5.7.1 Client was not authenticated 

Reason 

This error typically occurs when your outgoing mail server requires authentication, but your email client is not configured to provide it. 

Common causes include: 

• SMTP authentication is disabled in the email client  
• Incorrect outgoing mail server (SMTP) settings  
• Incorrect SMTP port configuration  
• SSL/TLS encryption is not enabled when required  
• The email client is attempting to send mail through a server that requires login credentials  

In most cases, the issue is related to incorrect email client configuration rather than a server problem. 

Fix 

To resolve the 530 Authentication Required error, make sure your email client is configured to authenticate with the outgoing mail server. 

Follow these general steps: 

1. Enable SMTP Authentication
   In your email client settings, locate the Outgoing Mail Server (SMTP) settings and enable the option that says “My outgoing server requires authentication.”
   
   Use the same login credentials as the incoming mail server.
    
2. Verify SMTP Settings
   Confirm that the outgoing or SMTP mail server settings are correct. Typical settings include:
   • SMTP Server: mail.(yourdomain.com) 
   • Username: Full email address 
   • Password: Email account password 
   • Port: 587 (TLS) or 465 (SSL) 
   • Encryption: SSL or TLS 
   
   Read our Email Setup Guide to find out the exact SMTP settings for your email.
    
3. Avoid Port 25
   Many internet service providers block Port 25, which can cause authentication errors. It is recommended to use Port 587 or 465 instead.
    
4. Update Saved Credentials
   
   If your password was recently changed, update it in the email client to ensure the correct credentials are used.
   After correcting the SMTP authentication settings, try sending the email again. The message should be delivered successfully once the email client properly authenticates with the mail server.