Not using qmail the way you are (incorrectly) assuming.
I am an end user not an email provider.
For example I use qmail to provide "inter-device email" on a local network of devices all belonging to the same user, and not connected to the internet. Not that I love email but these devices are sometimes "locked down" by default and email is one of the few ways to move files between devices without using the internet.
Another example is using qmail on a tap-based layer 2 overlay (not OpenVPN) to provide encrypted "peer-to-peer email". Each peer is running qmail-smtpd bound to a tap device. This was an experiment to prove encrypted email is easy.
qmail running under curvecpserver is another experiment.
I am an end user not an email provider.
For example I use qmail to provide "inter-device email" on a local network of devices all belonging to the same user, and not connected to the internet. Not that I love email but these devices are sometimes "locked down" by default and email is one of the few ways to move files between devices without using the internet.
Another example is using qmail on a tap-based layer 2 overlay (not OpenVPN) to provide encrypted "peer-to-peer email". Each peer is running qmail-smtpd bound to a tap device. This was an experiment to prove encrypted email is easy.
qmail running under curvecpserver is another experiment.