Sending Mail
************

To send an e-mail message in Emacs, type C-x m.  This selects and initializes a buffer named *mail*, where you can edit the text and headers of the message.  Finally, type C-c C-s or C-c C-c to send the message.

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 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) creates a new frame for the mail buffer.

Because the mail buffer is an ordinary Emacs buffer, you can switch to other buffers while in the middle of composing mail, and switch back later (or never).  If you type C-x m again when you have been composing another message but have not sent it, Emacs asks for confirmation before erasing the old message.  If you answer n, Emacs selects the mail buffer with its old contents, so you can finish the old message and send it.  C-u C-x m is another way to do this.  Sending the message marks the mail buffer ``unmodified,'' which avoids the need for confirmation when C-x m is next used.

If you want to send another message before finishing the current message, use the command M-x rename-uniquely to rename the current mail buffer (see Misc Buffer).  Then you can use C-x m to make a new mail buffer, and work with each mail buffer independently.

Before using Emacs to send mail, you may need to customize the variable send-mail-function if your system is not set up to deliver mail directly via SMTP (see Mail Sending).  In addition, you may need to customize user-mail-address if the system cannot receive mail via SMTP (see Mail Headers).

The Format of the Mail Buffer
=============================

An email message must contain certain pieces of information, called headers, which specify the message's sender, recipient(s), and so on.

At the top of the mail buffer is a set of header fields, where you can enter this information.  You can insert and edit header fields using ordinary editing commands.  See Header Editing, for commands specific to editing header fields.

Some header fields are automatically pre-initialized in the buffer, when appropriate; other headers, such as Date and Message-Id, are normally omitted from the mail buffer and created automatically when the message is sent.

The line in the buffer that says

     --text follows this line--

separates the header fields from the body (or text) of the message.  Everything above this line is treated as part of the headers; everything below it is treated as the body.  The delimiter line itself does not appear in the message actually sent.  The text used for the delimiter line is controlled by the variable mail-header-separator.

Here is an example of what the headers and text in the mail buffer might look like.

     To: gnu@example.org
     CC: lungfish@example.com, byob@example.net
     Subject: The Emacs Manual
     --text follows this line--
     Please ignore this message.

Mail Header Fields
==================

A header field in the mail buffer starts with a field name at the beginning of a line, terminated by a colon.  Upper and lower case are equivalent in field names (and in mailing addresses also).  After the colon and optional whitespace comes the contents of the field.

You can use any name you like for a header field, but normally people use only standard field names with accepted meanings.  Here is a table of commonly-used fields.  Emacs pre-initializes some of these, depending on various options you can set.  You can delete or alter any header field before you send the message, if you wish.

From
     The address of the sender (you).  This should be a valid mailing address, as replies will normally go there.  Emacs initializes this field using the variables user-full-name and user-mail-address; see below.

To
     The mailing address(es) to which the message is addressed.  To list more than one address, use commas (not spaces) to separate them.

Subject
     A piece of text saying what the message is about.  Most mail-reading programs can display a summary of messages, listing the subject of each message but not its text.

CC
     Additional mailing address(es) to send the message to.  This is like To, except that these readers should not regard the message as directed at them.

BCC
     Additional mailing address(es) to send the message to, which should not appear in the header of the message actually sent.  ``BCC'' stands for blind carbon copies.

FCC
     The name of one file, to which a copy of the sent message should be appended.  Emacs writes the message in mbox format, unless the file is in Babyl format (used by Rmail before Emacs 23), in which case Emacs writes Babyl.  If an Rmail buffer is visiting the file, Emacs updates it accordingly.  To specify more than one file, use several FCC fields, with one file name in each field.

Reply-to
     An address to which replies should be sent, instead of From. You can use this header if, for some reason, your From address is unable to receive replies.

Mail-reply-to
     This field takes precedence over Reply-to.  It is used because some mailing lists set the Reply-to field for their own purposes (a somewhat controversial practice).

Mail-followup-to
     This field contains one or more addresses.  It is typically used when you reply to a message from a mailing list that you are subscribed to. It usually indicates that you want replies to go to the list, and that you do not need an extra copy sent directly to you.

In-reply-to
     A piece of text describing the message you are replying to.  Some mail systems can use this information to correlate related pieces of mail. Normally, you never need to think about this, because it is filled in automatically when you reply to a message in Rmail (or any other mail program built into Emacs).

References
     The Message-Ids of previous related messages (a Message-Id is a unique identifier generated when a message is sent).  Like In-reply-to, this is normally set up automatically for you.

The To, CC, and BCC fields can appear any number of times, and each such header field can contain multiple addresses, separated by commas.  This way, you can specify any number of places to send the message.  These fields can also have continuation lines: one or more lines starting with whitespace, following the starting line of the field, are considered part of the field.  Here's an example of a To field with a continuation line:

     To: foo@example.net, this@example.net,
       bob@example.com

The default contents of the From header field are computed from the variables user-full-name and user-mail-address. On some operating systems, Emacs initializes these two variables using environment variables (see General Variables).  If this information is unavailable or wrong, you can customize the variables yourself (see Easy Customization).

The value of the variable mail-from-style specifies how to format the address in the From field:

nil
     Use just the address, as in king@grassland.com.

parens
     Use both address and full name, as in:

     king@grassland.com (Elvis Parsley).

angles
     Use both address and full name, as in:

     Elvis Parsley <king@grassland.com>.

any other value
     Use angles for most addresses.  However, if the address must be ``quoted'' to remain syntactically-valid under the angles format but not under the parens format, use parens instead.  This is the default.

You can direct Emacs to insert certain default headers into the mail buffer by setting the variable mail-default-headers to a string.  Then C-x m inserts this string into the message headers.  For example, here is how to add a Reply-to and FCC header to each message:

     (setq mail-default-headers
           "Reply-to: foo@example.com\nFCC: ~/Mail/sent")

If the default header fields are not appropriate for a particular message, edit them as necessary before sending the message.

Mail Aliases
============

You can define mail aliases, which are short mnemonic names that stand for mail addresses or groups of mail addresses.  By default, mail aliases are defined in the file ~/.mailrc.  You can specify a different file name to use, by setting the variable mail-personal-alias-file.

To define an alias in .mailrc, write a line in the following format:

     alias NICK FULLADDRESSES

This means that NICK should expand into FULLADDRESSES, where FULLADDRESSES can be either a single address, or multiple addresses separated with spaces.  For instance, to make maingnu stand for gnu@gnu.org plus a local address of your own, put in this line:

     alias maingnu gnu@gnu.org local-gnu

If an address contains a space, quote the whole address with a pair of double quotes, like this:

     alias jsmith "John Q. Smith <none@example.com>"

Note that you need not include double quotes around individual parts of the address, such as the person's full name.  Emacs puts them in if they are needed.  For instance, it inserts the above address as "John Q. Smith" <none@example.com>.

Emacs also recognizes ``include'' commands in .mailrc.  They look like this:

     source FILENAME

The .mailrc file is not unique to Emacs; many other mail-reading programs use it for mail aliases, and it can contain various other commands.  However, Emacs ignores everything except alias definitions and include commands.

Mail aliases expand as abbrevs---that is to say, as soon as you type a word-separator character after an alias (see Abbrevs).  This expansion takes place only within the To, From, CC, BCC, and Reply-to header fields (plus their Resent- variants); it does not take place in other header fields, such as Subject.

You can also insert an aliased address directly, using the command M-x mail-abbrev-insert-alias.  This reads an alias name, with completion, and inserts its definition at point.

Mail Commands
=============

The default major mode for the *mail* buffer is called Message mode.  It behaves like Text mode in many ways, but provides several additional commands on the C-c prefix, which make editing a message more convenient.

In this section, we will describe some of the most commonly-used commands available in Message mode. Message mode also has its own manual, where its features are described in greater detail.  See Message.

Mail Sending
------------

There are two commands to send a message you have been editing:

C-c C-c
     Send the message, and deselect the mail buffer (message-send-and-exit).

C-c C-s
     Send the message, and leave the mail buffer selected (message-send).

If you want to send a message and be done with it, type C-c C-c (mail-send-and-exit).  This sends the message and then either deletes the window or switches to another buffer.  It also ``buries'' the mail buffer, putting it at the lowest priority for reselection.  This is the usual command for sending a message.

The command C-c C-s (message-send) sends the message and marks the mail buffer unmodified, but leaves the buffer selected. Use this command if you want to modify the message (perhaps with new recipients) and send it again.

Sending a message runs the hook message-send-hook.

In a file-visiting buffer, sending the message does not clear the modified flag, because only saving the file should do that.  Also, you don't get a warning if you try to send the same message twice.

When you send a message containing non-ASCII characters, they need to be encoded with a coding system (see Coding Systems). Usually the coding system is specified automatically by your chosen language environment (see Language Environments).  You can explicitly specify the coding system for outgoing mail by setting the variable sendmail-coding-system (see Recognize Coding).  If the coding system thus determined does not handle the characters in a particular message, Emacs asks you to select the coding system to use, showing a list of possible coding systems.

The variable send-mail-function controls how the default mail user agent sends mail.  Its value should be a function, which can be one of the following:

sendmail-send-it
     Send mail using the system's default sendmail (or sendmail-compatible) program.  This is the default on Unix and GNU, and works provided the system is a valid mail host (that is, provided it can deliver mail via SMTP).

mailclient-send-it
     Pass the mail buffer on to the system's designated mail client (see mailclient.el).  This is the default on Mac OS X and MS-Windows.

smtpmail-send-it
     Send mail through an external mail host (e.g., your Internet service provider's SMTP server).  You will need to tell Emacs how to contact the SMTP server, by customizing the variables smtpmail-smtp-server and smtpmail-auth-credentials. See Emacs SMTP Library (Sending mail via SMTP).

feedmail-send-it
     This is similar to sendmail-send-it, but allows you to queue messages for later sending.  See the commentary section in the file feedmail.el for more information.

Mail Header Editing
-------------------

Message mode provides the following special commands to move to particular header fields and to complete addresses in headers.

C-c C-f C-t
     Move to the To header (message-goto-to).

C-c C-f C-s
     Move to the Subject header (message-goto-subject).

C-c C-f C-c
     Move to the CC header (message-goto-cc).

C-c C-f C-b
     Move to the BCC header (message-goto-bcc).

C-c C-f C-r
     Move to the Reply-To header (message-goto-reply-to).

C-c C-f C-f
     Move to the Mail-Followup-To header field (message-goto-followup-to).

C-c C-f C-w
     Add a new FCC header field, with file-name completion (message-goto-fcc).

C-c C-b
     Move to the start of the message body (message-goto-body).

TAB
     Complete a mailing address (message-tab).

The commands to move point to particular header fields are all based on the prefix C-c C-f (C-f is for ``field'').  If the field in question does not exist, the command creates one (the exception is mail-fcc, which creates a new field each time).

The command C-c C-b (message-goto-body) moves point to just after the header separator line---that is, to the beginning of the body.

While editing a header field that contains addresses, such as To:, CC: and BCC:, you can complete an address by typing TAB (message-tab).  This attempts to insert the full name corresponding to the address based on a couple of methods, including EUDC, a library that recognizes a number of directory server protocols (see EUDC (The Emacs Unified Directory Client)).  Failing that, it attempts to expand the address as a mail alias (see Mail Aliases).  If point is on a header field that does not take addresses, or if it is in the message body, then TAB just inserts a tab character.

Citing Mail
-----------

C-c C-y
     Yank the selected message from Rmail (message-yank-original).

C-c C-q
     Fill each paragraph cited from another message (message-fill-yanked-message).

You can use the command C-c C-y (message-yank-original) to cite a message that you are replying to.  This inserts the text of that message into the mail buffer.  This command is active only when the mail buffer is invoked from a mail program running in Emacs, such as Rmail.

By default, Emacs inserts the string > in front of each line of the cited text; this prefix string is specified by the variable message-yank-prefix.  If you call message-yank-original with a prefix argument, the citation prefix is not inserted.

After using C-c C-y, you can type C-c C-q (message-fill-yanked-message) to fill the paragraphs of the cited message.  One use of C-c C-q fills all such paragraphs, each one individually.  To fill a single paragraph of the quoted message, use M-q.  If filling does not automatically handle the type of citation prefix you use, try setting the fill prefix explicitly.  See Filling.

You can customize mail citation through the hook mail-citation-hook.  For example, you can use the Supercite package, which provides more flexible citation (see Introduction (Supercite)).

Mail Miscellany
---------------

You can attach a file to an outgoing message by typing C-c C-a (mml-attach-file) in the mail buffer.  Attaching is done using the Multipurpose Internet Mail Extensions (MIME) standard.

The mml-attach-file command prompts for the name of the file, and for the attachment's content type, description, and disposition.  The content type is normally detected automatically; just type RET to accept the default.  The description is a single line of text that the recipient will see next to the attachment; you may also choose to leave this empty.  The disposition is either inline (the default), which means the recipient will see a link to the attachment within the message body, or attachment, which means the link will be separate from the body.

The mml-attach-file command is specific to Message mode; in Mail mode use mail-add-attachment instead.  It will prompt only for the name of the file, and will determine the content type and the disposition automatically.  If you want to include some description of the attached file, type that in the message body.

The actual contents of the attached file are not inserted into the mail buffer.  Instead, some placeholder text is inserted into the mail buffer, like this:

     <#part type="text/plain" filename="~/foo.txt" disposition=inline>
     <#/part>

When you type C-c C-c or C-c C-s to send the message, the attached file will be delivered with it.

While composing a message, you can do spelling correction on the message text by typing M-x ispell-message.  If you have yanked an incoming message into the outgoing draft, this command skips what was yanked, but it checks the text that you yourself inserted (it looks for indentation or mail-yank-prefix to distinguish the cited lines from your input).  See Spelling.

Turning on Message mode (which C-x m does automatically) runs the normal hooks text-mode-hook and message-mode-hook. Initializing a new outgoing message runs the normal hook message-setup-hook; you can use this hook if you want to make changes to the appearance of the mail buffer.  See Hooks.

The main difference between these hooks is just when they are invoked.  Whenever you type C-x m, message-mode-hook runs as soon as the mail buffer is created.  Then the message-setup function inserts the default contents of the buffer.  After these default contents are inserted, message-setup-hook runs.

If you use C-x m to continue an existing composition, message-mode-hook runs immediately after switching to the mail buffer.  If the buffer is unmodified, or if you decide to erase it and start again, message-setup-hook runs after the default contents are inserted.

Mail Signature
==============

You can add a standard piece of text---your mail signature---to the end of every message.  This signature may contain information such as your telephone number or your physical location. The variable mail-signature determines how Emacs handles the mail signature.

The default value of mail-signature is t; this means to look for your mail signature in the file ~/.signature.  If this file exists, its contents are automatically inserted into the end of the mail buffer.  You can change the signature file via the variable mail-signature-file.

If you change mail-signature to a string, that specifies the text of the signature directly.

If you change mail-signature to nil, Emacs will not insert your mail signature automatically.  You can insert your mail signature by typing C-c C-w (message-insert-signature) in the mail buffer.  Emacs will look for your signature in the signature file.

By convention, a mail signature should be marked by a line whose contents are -- .  If your signature lacks this prefix, it is added for you.  The remainder of your signature should be no more than four lines.

Mail Amusements
===============

M-x spook adds a line of randomly chosen keywords to an outgoing mail message.  The keywords are chosen from a list of words that suggest you are discussing something subversive.

The idea behind this feature is the suspicion that the NSA (The US National Security Agency.) and other intelligence agencies snoop on all electronic mail messages that contain keywords suggesting they might find them interesting.  (The agencies say that they don't, but that's what they would say.)  The idea is that if lots of people add suspicious words to their messages, the agencies will get so busy with spurious input that they will have to give up reading it all.  Whether or not this is true, it at least amuses some people.

You can use the fortune program to put a ``fortune cookie'' message into outgoing mail.  To do this, add fortune-to-signature to mail-setup-hook:

     (add-hook 'mail-setup-hook 'fortune-to-signature)

You will probably need to set the variable fortune-file before using this.

Mail-Composition Methods
========================

In this chapter we have described the usual Emacs mode for editing and sending mail---Message mode.  This is only one of several available modes.  Prior to Emacs 23.2, the default mode was Mail mode, which is similar to Message mode in many respects but lacks features such as MIME support.  Another available mode is MH-E (see MH-E (The Emacs Interface to MH)).

You can choose any of these mail user agents as your preferred method for editing and sending mail.  The commands C-x m, C-x 4 m and C-x 5 m use whichever agent you have specified; so do various other parts of Emacs that send mail, such as the bug reporter (see Bugs).  To specify a mail user agent, customize the variable mail-user-agent.  Currently, legitimate values include message-user-agent (Message mode) sendmail-user-agent (Mail mode), gnus-user-agent, and mh-e-user-agent.

If you select a different mail-composition method, the information in this chapter about the mail buffer and Message mode does not apply; the other methods use a different format of text in a different buffer, and their commands are different as well.

Similarly, to specify your preferred method for reading mail, customize the variable read-mail-command.  The default is rmail (see Rmail).