Thank for your great plugin
I use Pie Register to customize a registration procedure and authentication on the site: copperprodev.coppernic.fr/
The general website address email is email@example.com. The address registered for the administrator’s notifications is also firstname.lastname@example.org.
However – as you can see on the screenshot, when a user receives mail from the administrator, the sender address is email@example.com.
Can you please confirm if you are using any “SMTP” or WP Email enhancement plugin that would modifying it? This is weird it should follow the given FROM email unless any other plugin or theme explicitly modifies it.
PLUGINS LIST :
Advanced Code Editor
Media File Manager
User Role Editor
User Specific Content
WPML Multilingual CMS
Email Login (Desactivated and deleted, same issue after)