SMTP Error 533 is caused by issues with recipient authentication or email content. It often occurs when the recipient’s email address is invalid, the domain is non-existent or has DNS problems, or the email content violates the server’s policies. Additionally, this error can signify a lack of SMTP authentication.
Resolving the Error – Solution
To tackle the SMTP Error 533:
- Check Recipient Details: Carefully verify the recipient’s email address for accuracy and validity.
- Inspect Recipient Domain: Make sure the domain is functioning properly, checking for any DNS issues.
- Examine Email Content: Adjust your email’s content to align with the recipient server’s policies, ensuring it doesn’t trigger spam filters.
- Activate SMTP Authentication: Confirm that SMTP authentication is enabled in your email settings. For WordPress users, an SMTP plugin like Easy WP SMTP helps in configuring SMTP settings correctly and reduces the likelihood of your emails being marked as spam.