\chapter {Delivery Formats}

\section {Overview}

In many cases, local delivery will proceed by delivery into a mailbox of
well defined format.  These are defined here.  Where appropriate, standard
library routines to facilitate manipulation of these formats are also given.

\section {RFC~822/MMDF format}

The standard RFC~822/MMDF mailbox format is a single file with
messages in separated by delimeters. The delimeter is tailorable so
may be any string - but normally it is a sequence of four control-A's
and a newline. There are two delimeters, which may be the same string
or may be different. This format is not expected to used much once
suitable user agents have been written.
