Mail is an ancient method of exchanging annoying information like bills. At some point people realised that that's stupid and created Email, which explicitly disallows sending bills. The existence, therefore, of the Proton Mail billing service is quite the scientific marvel.
Mail's last use case remains the efficient distribution of pipe bombs.
Sending packages
If you want to be slightly less annoying you can send packages via mail. Hell, you can also receive them. Just imagine that.
Famous mail users
