If (in the web client) you go into Administration -> Dashboard then in the sidebar click on General, then scroll down, there’s an option named Login Disclaimer, which lets you add a message to the login screen for the web client.
I don’t think there’s any setting or mod that adds a MOTD like you’re thinking of, that’s just the closest thing I can think of off the top of my head
If (in the web client) you go into Administration -> Dashboard then in the sidebar click on General, then scroll down, there’s an option named Login Disclaimer, which lets you add a message to the login screen for the web client.
I don’t think there’s any setting or mod that adds a MOTD like you’re thinking of, that’s just the closest thing I can think of off the top of my head