32 Sending Mail
To send an email message from Emacs, type C-x m. This
switches to a buffer named *unsent mail*, where you can edit
the text and headers of the message. When done, type C-c C-s or
C-c C-c to send it.
C-x m
Begin composing mail ( compose-mail).
C-x 4 m
Likewise, in another window ( compose-mail-other-window).
C-x 5 m
Likewise, but in a new frame ( compose-mail-other-frame).
C-c C-s
In the mail buffer, send the message ( message-send).
C-c C-c
In the mail buffer, send the message and bury the buffer
( message-send-and-exit).
The mail buffer is an ordinary Emacs buffer, so you can switch to
other buffers while composing the mail. If you want to send another
message before finishing the current one, type C-x m again to
open a new mail buffer whose name has a different numeric suffix
(see Miscellaneous Buffer Operations). (This only works if you use the default
Message mode to compose email; see Mail Commands.) If you know
that you’d like to continue composing the unsent message you were
editing, invoke this command with a prefix argument, C-u C-x m, and Emacs will switch to the last mail buffer you used and let
you pick up editing the message where you left off.
The command C-x 4 m ( compose-mail-other-window) does
the same as C-x m, except it displays the mail buffer in a
different window. The command C-x 5 m
( compose-mail-other-frame) does it in a new frame.
When you type C-c C-c or C-c C-s to send the mail, Emacs
may ask you how it should deliver the mail—either directly via SMTP,
or using some other method. See Mail Sending, for details.