- Plesk for Linux
PHP script sends mail using server IP address instead of domain IP address.
Send from domain IP addresses and use domain names in SMTP greeting option is enabled in Tools & Settings > Mail Server Settings :
PHP is running as FPM application :
Plesk bug with ID #PPPM-4199 , that is planned to be fixed in future Plesk updates.
As a workaround, change PHP handler in Domains > example.com > PHP Settings to FastCGI application served by Apache .