posting = P = PostScript

postmaster n.

The email contact and maintenance person at a site connected to the Internet or UUCPNET. Often, but not always, the same as the admin. The Internet standard for electronic mail (RFC-822) requires each machine to have a `postmaster' address; usually it is aliased to this person.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.