@settitle Emacs SMTP Library
@syncodeindex vr fn
@copying
-Copyright @copyright{} 2003 Free Software Foundation, Inc.
+Copyright @copyright{} 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
@quotation
Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.1 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
-``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
-Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
-license is included in the section entitled ``GNU Free Documentation
-License'' in the Emacs manual.
+under the terms of the GNU Free Documentation License, Version 1.2 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with the Front-Cover texts being ``A GNU Manual'',
+and with the Back-Cover Texts as in (a) below. A copy of the license
+is included in the section entitled ``GNU Free Documentation License''
+in the Emacs manual.
(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
this GNU Manual, like GNU software. Copies published by the Free
@dircategory Emacs
@direntry
-* Emacs SMTP Library: (smtpmail). Emacs library for sending mail via SMTP.
+* SMTP: (smtpmail). Emacs library for sending mail via SMTP.
@end direntry
@titlepage
* How Mail Works:: Brief introduction to mail concepts.
* Emacs Speaks SMTP:: How to use the SMTP library in Emacs.
* Authentication:: Authenticating yourself to the server.
-* Queued delivery:: Sending mail without an Internet connection.
+* Queued delivery:: Sending mail without an internet connection.
* Server workarounds:: Mail servers with special requirements.
* Debugging:: Tracking down problems.
@cindex SMTP
@cindex MTA
- On the Internet, mail is sent from mail host to mail host using the
+ On the internet, mail is sent from mail host to mail host using the
simple mail transfer protocol (SMTP). To send and receive mail, you
must get it from and send it to a mail host. Every mail host runs a
-mail transger agent (MTA) such as Exim that accepts mails and passes
+mail transfer agent (MTA) such as Exim that accepts mails and passes
them on. The communication between a mail host and other clients does
not necessarily involve SMTP, however. Here is short overview of what
is involved.
delivery agents often allow you to filter and munge your mails before
you get to see it. When your computer is that mail host, this file is
called a spool, and sometimes located in the directory
-/var/spool/mail/. All your MUA has to do is read mail from the spool,
-then.
+@file{/var/spool/mail/}. All your MUA has to do is read mail from the
+spool, then.
@cindex POP3
@cindex IMAP
- When your computer is not always connected to the Internet, you
+ When your computer is not always connected to the internet, you
must get the mail from the remote mail host using a protocol such as
POP3 or IMAP. POP3 essentially downloads all your mail from the mail
host to your computer. The mail is stored in some file on your
have it take care of delivering it to the final destination, rather
than letting the MTA on your local system take care of it. This can
be useful if you don't have a MTA set up on your host, or if your
-machine is often disconnected from the Internet.
+machine is often disconnected from the internet.
Sending mail via SMTP requires configuring your mail user agent
(@pxref{Mail Methods,,,emacs}) to use the SMTP library. How to do
@vindex SMTPSERVER
The variable @code{smtpmail-smtp-server} controls the hostname of
the server to use. It is a string with an IP address or hostname. It
-defaults to the contents of the @code{SMTPSERVER} environment
+defaults to the contents of the @env{SMTPSERVER} environment
variable, or, if empty, the contents of
@code{smtpmail-default-smtp-server}.
@cindex SASL
@cindex CRAM-MD5
-@cindex PLAIN
@cindex LOGIN
@cindex STARTTLS
Many environments require SMTP clients to authenticate themselves
variables contains the authentication information needed for this.
The first variable, @code{smtpmail-auth-credentials}, instructs the
SMTP library to use a SASL authentication step, currently only the
-CRAM-MD5, PLAIN and LOGIN-MD5 mechanisms are supported and will be
-selected in that order if the server supports them. The second
-variable, @code{smtpmail-starttls-credentials}, instructs the SMTP
-library to connect to the server using STARTTLS. This means the
-protocol exchange can be integrity protected and confidential by using
-TLS, and optionally also authentication of the client. It is common
-to use both these mechanisms, e.g., to use STARTTLS to achieve
-integrity and confidentiality and then use SASL for client
+CRAM-MD5 and LOGIN mechanisms are supported and will be selected in
+that order if the server support both.
+
+The second variable, @code{smtpmail-starttls-credentials}, instructs
+the SMTP library to connect to the server using STARTTLS. This means
+the protocol exchange may be integrity protected and confidential by
+using TLS, and optionally also authentication of the client. This
+feature uses the elisp package @file{starttls.el} (see it for more
+information on customization), which in turn require that at least one
+of the following external tools are installed:
+
+@enumerate
+@item
+The GNUTLS command line tool @samp{gnutls-cli}, you can get it from
+@url{http://www.gnu.org/software/gnutls/}. This is the recommended
+tool, mainly because it can verify the server certificates.
+
+@item
+The @samp{starttls} external program, you can get it from
+@file{starttls-*.tar.gz} from @uref{ftp://ftp.opaopa.org/pub/elisp/}.
+@end enumerate
+
+It is not uncommon to use both these mechanisms, e.g., to use STARTTLS
+to achieve integrity and confidentiality and then use SASL for client
authentication.
@table @code
connects to a host on a certain port, this variable is searched to
find a matching entry for that hostname and port. If an entry is
found, the authentication process is invoked and the credentials are
-used. The hostname field follows the same format as
+used.
+
+The hostname field follows the same format as
@code{smtpmail-smtp-server} (i.e., a string) and the port field the
same format as @code{smtpmail-smtp-service} (i.e., a string or an
integer). The username and password fields, which either can be
-@samp{nil} to indicate that the user is queried for the value
+@code{nil} to indicate that the user is prompted for the value
interactively, should be strings with the username and password,
respectively, information that is normally provided by system
administrators.
tuples with hostname, port, name of file containing client key, and
name of file containing client certificate. The processing is similar
to the previous variable. The client key and certificate may be
-@samp{nil} if you do not wish to use client authentication. The use
-of this variable requires the @samp{starttls} external program to be
-installed, you can get @file{starttls-*.tar.gz} from
-@uref{ftp://ftp.opaopa.org/pub/elisp/}.
+@code{nil} if you do not wish to use client authentication.
@end table
The following example illustrates what you could put in
@file{~/.emacs} to enable both SASL authentication and STARTTLS. The
server name (@code{smtpmail-smtp-server}) is @var{hostname}, the
server port (@code{smtpmail-smtp-service}) is @var{port}, and the
-username and password are @var{username} and "@var{password}
+username and password are @var{username} and @var{password}
respectively.
@example
;; Authenticate using this username and password against my server.
(setq smtpmail-auth-credentials
'(("@var{hostname}" "@var{port}" "@var{username}" "@var{password}")))
+
+;; Note that if @var{port} is an integer, you must not quote it as a
+;; string. Normally @var{port} should be the integer 25, and the example
+;; become:
+(setq smtpmail-auth-credentials
+ '(("@var{hostname}" 25 "@var{username}" "@var{password}")))
+
;; Use STARTTLS without authentication against the server.
(setq smtpmail-starttls-credentials
'(("@var{hostname}" "@var{port}" nil nil)))
@chapter Queued delivery
@cindex Dialup connection
-If you connect to the Internet via a dialup connection, or for some
-other reason doesn't have permanent Internet connection, sending mail
+If you connect to the internet via a dialup connection, or for some
+other reason don't have permanent internet connection, sending mail
will fail when you are not connected. The SMTP library implements
-queued delivery, and the following variable control its behaviour.
+queued delivery, and the following variable control its behavior.
@table @code
@item smtpmail-queue-mail
@vindex smtpmail-queue-mail
The variable @code{smtpmail-queue-mail} controls whether a simple
off line mail sender is active. This variable is a boolean, and
-defaults to @samp{nil} (disabled). If this is non-nil, mail is not
-sent immediately but rather queued in the directory
+defaults to @code{nil} (disabled). If this is non-@code{nil}, mail is
+not sent immediately but rather queued in the directory
@code{smtpmail-queue-dir} and can be later sent manually by invoking
@code{smtpmail-send-queued-mail} (typically when you connect to the
-Internet).
+internet).
-@item smtpmail-queue-mail
+@item smtpmail-queue-dir
@vindex smtpmail-queue-dir
The variable @code{smtpmail-queue-dir} specifies the name of the
directory to hold queued messages. It defaults to
@findex smtpmail-send-queued-mail
The function @code{smtpmail-send-queued-mail} can be used to send
any queued mail when @code{smtpmail-queue-mail} is enabled. It is
-typically invoked interactively with @kbd{M-x RET
-smtpmail-send-queued-mail RET} when you are connected to the Internet.
+typically invoked interactively with @kbd{M-x
+smtpmail-send-queued-mail RET} when you are connected to the internet.
@node Server workarounds
@chapter Server workarounds
The variable @code{smtpmail-sendto-domain} makes the SMTP library
add @samp{@@} and the specified value to recipients specified in the
message when they are sent using the @code{RCPT TO} command. Some
-configurations of sendmail requires this behaviour. Don't bother to
+configurations of sendmail requires this behavior. Don't bother to
set this unless you have get an error like:
@example
@contents
@bye
+
+@ignore
+ arch-tag: 6316abdf-b366-4562-87a2-f37e8f894b6f
+@end ignore