Function: mail

Edit a message to be sent. Prefix arg means resume editing (don't erase).
When this function returns, the buffer `*mail*' is selected.
The value is t if the message was newly initialized; otherwise, nil.

Optionally, the signature file `mail-signature-file' can be inserted at the
end; see the variable `mail-signature'.

Uses keymap `mail-mode-map', which is not currently defined.

While editing message, type M-x mail-send-and-exit to send the message and exit.

Various special commands starting with C-c are available in sendmail mode
to move to message header fields:

Uses keymap `mail-mode-map', which is not currently defined.

If `mail-self-blind' is non-nil, a BCC to yourself is inserted
when the message is initialized.

If `mail-default-reply-to' is non-nil, it should be an address (a string);
a Reply-to: field with that address is inserted.

If `mail-archive-file-name' is non-nil, an FCC field with that file name
is inserted.

The normal hook `mail-setup-hook' is run after the message is
initialized. It can add more default fields to the message.

The first argument, NOERASE, determines what to do when there is
an existing modified `*mail*' buffer. If NOERASE is nil, the
existing mail buffer is used, and the user is prompted whether to
keep the old contents or to erase them. If NOERASE has the value
`new', a new mail buffer will be created instead of using the old
one. Any other non-nil value means to always select the old
buffer without erasing the contents.

The second through fifth arguments,
TO, SUBJECT, IN-REPLY-TO and CC, specify if non-nil
the initial contents of those header fields.
These arguments should not have final newlines.
The sixth argument REPLYBUFFER is a buffer which contains an
original message being replied to, or else an action
of the form (FUNCTION . ARGS) which says how to insert the original.
Or it can be nil, if not replying to anything.
The seventh argument ACTIONS is a list of actions to take
if/when the message is sent. Each action looks like (FUNCTION . ARGS);
when the message is sent, we apply FUNCTION to ARGS. This is how Rmail arranges to mark messages `answered'. (fn &optional NOERASE TO SUBJECT IN-REPLY-TO CC REPLYBUFFER ACTIONS RETURN-ACTION)