V8/usr/src/cmd/Mail/manual/cmds/write

.ip \fBwrite\fP
The
.b save
command always writes the entire message, including the headers,
into the file.  If you want to write just the message itself, you
can use the
.b write
command.  The
.b write
command has the same syntax as the
.b save
command, and can be abbreviated to simply
.b w .
Thus, we could write the second message by doing:
.(l
w 2 file.c
.)l
As suggested by this example, the
.b write
command is useful for such tasks as sending and receiving
source program text over the message system.