The current `smtp.config.php` file does not work as advertised in the documentation. Both `MAIL_FROM_ADDRESS` and `MAIL_DOMAIN` should be optional as the Nextcloud instance may use multiple _from addresses_ like no-reply@example.com or passwordreset-no-reply@example.com (or similar). It may also just use the domain name from the instance instead of a configured one.
I tested this PR on NC 21 as I don't have access to the previous versions at the moment. I propose to leave NC 19 annd 20 as they are and to continue with this `smtp.config.php` from version 21 forward.
Signed-off-by: 0x47 <0x47@users.noreply.github.com>