smtpd(8) on macOS

The text 3736393f738f, as macOS 10.12.6, macOS 10.12.5, macOS 10.12.4, macOS 10.12.3, macOS 10.12.2, macOS 10.12.1, macOS 10.12 shipped it.

Postfix SMTP server

smtpd(8) on macOS now