[dhc02]

I couldn't think of a use case for something this. For anyone else like me, the readme outlines one near the bottom which seems genuinely nice:

Set this up, allow no-auth sending from any address on your LAN, and then spinning up new local services that need outgoing mail is easy, because you can just give them the IP of the relay and omit credentials.

[toinbox]

Exactly - the homelab case is the most common one. Instead of putting Gmail app passwords into 10 different devices, you configure it once in SimpleRelay and point everything at one endpoint.

[_superposition_]

At acme corp we used to spoof bonus emails from management through the smtp relay. Good times. Not so good security.