- Plesk for Windows
Unable to send an email via PHP script on Windows.
The following error is displayed upon accessing the script in a web browser if
ini_set( 'display_errors', 1 );is defined in the script:
CONFIG_TEXT: Warning: mail(): SMTP server response: 503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server.
Localhost addresses are not added to Tools & Settings > Mail Server Settings > White List.
SMTP server requires authentification in order to send mail to non-local addresses.
Define proper authorization credentials in the mail script.
Add localhost addresses to the whitelist. In this case, local client will not be bound to authorize itself in order to send mail. However, emails will not be counted towards the Outgoing Mail Limit.
In order to do it, Log into Plesk and add following addresses under Plesk > Tools & Settings > Mail Server Settings > White List > Add Network: