Symptoms
You receive the following error when sending or receiving mail:
CONFIG_TEXT: 550-Please turn on SMTP Authentication in your mail client
Cause
This issue can occur for many reasons. You should consult these options for review.
Resolution
Warning: Way to the Web Ltd. (the company behind ConfigServer) announced it has closed permanently as of August 31, 2025; however, their free scripts will remain available under the GPLv3 license.
cPanel now provides a fork of CSF:
cPanel will provide its own fork of CSF starting Feb 25th, 2026
If you use ConfigServer Security & Firewall (CSF), there is a potential conflict between CSF and the "Restrict outgoing SMTP to root, Exim, and mailman (FKA SMTP Tweak)" Tweak Setting.
If, when sending a message from one provider to your server, you encounter this 550 error message, despite not using a mail client, the cause of this error is likely to be related to the mail routing settings.
If the MX record points to this server, you must set the mail routing configuration to local.
What is The Difference Between Remote Vs. Local Mail Exchange Within "Email Routing"?
Some users may have their mail client configured in a way where sending mail does not authenticate with a password. This can be confirmed by changing this setting:
How to enable relaying of mail from same IP of users who have already authenticated.
If this is the case, the user should adjust their mail client settings to authenticate when sending mail.
If you attempt to send mail from a script, and it is failing with this error, you should review the restrictions of the SMTP Restriction Tweak:
If the account was recently transferred, there also may be a configuration error to review:
Comments
0 comments
Article is closed for comments.