Check Site admin > Users > Permissions > Site Administrators. It’s coming from the “Main” site admin.
But that particular email only goes to other site admins so it’s appropriate to come from the primary admin.
You can also turn off that notification message at Site admin > Server > Update notifications.
Or you can disable update checking completely through the config.php file - https://docs.moodle.org/311/en/Available_update_notifications#Disabling_update_notifications
But that particular email only goes to other site admins so it’s appropriate to come from the primary admin.
You can also turn off that notification message at Site admin > Server > Update notifications.
Or you can disable update checking completely through the config.php file - https://docs.moodle.org/311/en/Available_update_notifications#Disabling_update_notifications