Email sending error - 530 Authentication Required

This guide explains what causes the 530 Authentication Required error and why it occurs when sending emails. By using this guide, you’ll learn how to authenticate your email properly so your messages can be sent successfully.

Issue

Users encounter the 530 Authentication Required error after attempting to send an email without authenticating with the mail server. Email remains in the Outbox or in mail server logs. This error can appear in several places, such as: 

• 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

Cause

This error usually happens when the outgoing mail server requires authentication but the 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.

Solution

To resolve the 530 Authentication Required error, ensure that your email client is properly 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.