Error Messages

Most Common Email Error Messages and Quick Fixes

When sending or receiving emails, various error messages may occur. Here are the most common error messages and quick fixes to resolve them: 

550 – Requested action not taken: Mailbox unavailable

Meaning: 

This error means that the recipient's email address is invalid or does not exist. 

Quick Fix: 

• Double-check if the recipient's email address is spelled correctly. 
• Ask the recipient if there have been any changes to their email address. 

554 – Transaction failed

Meaning: 

The email server is refusing to deliver the message. This can happen if the email is flagged as spam or if the server has a general issue. 

Quick Fix: 

• Check the email content for any terms that could be recognized as spam. 
• Ensure SPF, DKIM, and DMARC are correctly configured to confirm your domain’s authenticity. 

552 – Quota exceeded (Mailbox storage limit exceeded)

Meaning: 

The recipient’s mailbox has reached its storage limit, and the email cannot be delivered. 

Quick Fix: 

• Contact the recipient and ask them to free up some storage space. 
• Wait and try again later. 

451 – Requested action aborted: Local error in processing

Meaning: 

This is a temporary issue with the recipient's email server, often due to maintenance or server problems. 

Quick Fix: 

• Wait a while and try sending the email again later. 
• If the problem persists, contact your email provider's support. 

421 – Service not available, closing transmission channel

Meaning: 

The mail server is currently unavailable, possibly due to overload or maintenance. 

Quick Fix: 

• Wait a few minutes and try again. 
• Ensure that your email service is functioning correctly. 

535 – Authentication failed

Meaning: 

Login to the SMTP server failed. The username or password may be incorrect. 

Quick Fix: 

• Verify that the correct login credentials (username and password) are entered in the email settings. 
• Ensure the correct SMTP server and ports are being used. 

450 – Requested mail action not taken: Mailbox unavailable

Meaning: 

The recipient's mail server is not accepting emails at the moment, possibly due to a locked, inactive, or full mailbox. 

Quick Fix: 

• Wait a while and try again later. 
• Ask the recipient if the mailbox is active or if there are storage issues. 

553 – Relaying denied

Meaning: 

The email server is refusing to send the message because authentication is not enabled to send emails via that server. 

Quick Fix: 

• Ensure you are using the correct SMTP server and have enabled authentication for the outgoing email server. 
• Check your email settings for accuracy. 

550 5.7.1 – Relay access denied

Meaning: 

This error occurs when the email server blocks the message because you are not authenticated to send emails through that server. 

Quick Fix: 

• Ensure SMTP authentication is enabled in your email settings. 
• Double-check that the correct login credentials and SMTP settings are used. 

By addressing these common issues, you can quickly resolve email errors and ensure your messages are successfully delivered.