3.1 Messages

A message, or email message, is the basic unit of electronic mail. The format of a message is defined by RFC 822. Nearly all email messages are transmitted over the internet, which means that the contents of such messages are further constrained by the SMTP protocol that is used for internet message transmission, as defined in RFC 821.

In brief, the primary constraints on an email message is that it may contain only printable US-ASCII characters, and that lines of text in the message may not exceed 1000 characters, including the carriage-return/linefeed pair at the end of each line. These constraints are fairly strict, and do not permit messages to contain text in languages other than English, or to contain non-textual data such as images. The Multipurpose Internet Mail Extensions (MIME, RFC 2045) provide a way to encode other kinds of text and data so that they can be carried in an email message. Most modern email software supports the MIME standard; one notable exception is Emacs Rmail.

3.2 Folders

Another important concept is a means for grouping messages together. All email software provides some means for doing this, and IMAIL is no exception. IMAIL provides objects called folders. A folder is just an object that holds an arbitrary number of email messages. Messages can be added to a folder, deleted from a folder, and moved or copied from one folder to another.

In IMAIL, the concept of the folder is used to embrace different grouping mechanisms. This is because IMAIL provides a uniform means for accessing different kinds of email systems. In particular, IMAIL supports access to Emacs Rmail files (also known as BABYL files, for historical reasons), to unix mailbox files (sometimes called mbox files), and to IMAP mailboxes. Each of these grouping mechanisms, although implemented very differently, is viewed as a folder by IMAIL. With some exceptions, each of these different types of folder are treated exactly the same by IMAIL. Finally, because IMAIL is extensible, other types of folders may be supported in the future.

3.3 Containers

Folders can themselves be grouped together inside objects called containers. A container is an object that holds folders, much in the same way that a folder holds messages. As for folders, the concept of a container is a generalization of the different kinds of mechanisms used by the underlying mail technology. So, for example, the container of a file folder is the directory holding that file.

IMAP containers are a little different: each IMAP mailbox is capable of holding other mailboxes. What this means is that, from IMAIL’s point of view, an IMAP mailbox is both a folder object and a container object at the same time. However, when IMAIL views an IMAP mailbox as a container, it is treated differently than when it is viewed as a folder, and consequently different notation is used in each case.

3.4 URLs

In email software like Rmail, where mail is stored in files, filenames are used to refer to groups of messages. Since IMAIL folders often aren’t files, it is necessary to use a more general kind of reference for folders. To this end, IMAIL uses Uniform Resource Locators (URLs) to refer to folders.² IMAIL currently supports two kinds of URLs: IMAP URLs and file URLs.

• IMAP URLs
• File URLs
• Container URLs

imap://uname@hostname:port/mailbox

imap://localhost/inbox
imap://localhost/inbox/sysadmin
imap://localhost/inbox/sysadmin/equipment

file://hostname/pathname

file:///pathname

file:/pathname

C:\My Documents\Mail\My Mail.rmail

file://localhost/C:/My%20Documents/Mail/My%20Mail.rmail

imap://localhost/inbox/sysadmin/equipment

imap://localhost/inbox/sysadmin/

imap://localhost/inbox/sysadmin

3.5 Server Connections

Unlike a file folder, in which the folder’s contents are always available, access to an IMAP folder requires an active network connection to the IMAP server. This adds an additional layer of complexity to the mail-reading process, which is reflected in the connection state of an IMAP folder.

An IMAP folder can be in one of two states: online, meaning that there is an established network connection between IMAIL and the IMAP server, and offline when there is not. IMAIL is, at present, a very simple IMAP mail reader: it must be online to read and manipulate mail messages. Mail readers that have this property are said to operate in online mode.⁶ Do not confuse the online state with online mode. When we refer to online or offline in this document, it always means the corresponding state.

When an IMAP folder is selected in an IMAIL buffer, the modeline for that buffer shows either ‘online’ or ‘offline’ to indicate the folder’s connection state. Normally, an IMAP folder goes online when it is first selected, and stays online indefinitely until it is explicitly disconnected.⁷ Commands that break the connection are explicitly pointed out in their descriptions below; most other commands will force an IMAP folder into the online state if it is offline.

4.1 Navigation

The most basic thing to do with a message is to read it. The way to do this in IMAIL is to select the message. The usual practice is to move sequentially through the folder, since this is the order of receipt of messages. When you enter IMAIL, you are positioned at the first message that you have not yet seen (that is, the first one that has the ‘unseen’ flag; see Flags). Move forward to see the other new messages; move backward to reexamine old messages.

n

Move to the next nondeleted message, skipping any intervening deleted messages (imail-next-undeleted-message).

p

Move to the previous nondeleted message (imail-previous-undeleted-message).

M-n

Move to the next message, including deleted messages (imail-next-message).

M-p

Move to the previous message, including deleted messages (imail-previous-message).

j

Move to the first message. With argument n, move to message number n (imail-select-message).

>

Move to the last message (imail-last-message).

<

Move to the first message (imail-first-message).

M-u

Move to the first unseen message (imail-first-unseen-message).

M-s string RET

Move to the next message containing a match for string (imail-search).

M-- M-s string RET

Move to the previous message containing a match for string.

C-c C-n

Move to the next message with the same subject (imail-next-same-subject).

C-c C-p

Move to the previous message with the same subject (imail-previous-same-subject).

n and p are the usual way of moving among messages in IMAIL. They move through the messages sequentially, but skip over deleted messages, which is usually what you want to do. Their command definitions are named imail-next-undeleted-message and imail-previous-undeleted-message. If you do not want to skip deleted messages—for example, if you want to move to a message to undelete it—use the variants M-n and M-p (imail-next-message and imail-previous-message). A numeric argument to any of these commands serves as a repeat count.

In IMAIL, you can specify a numeric argument by typing just the digits. You don’t need to type C-u first.

The M-s (imail-search) command is IMAIL’s version of search. The usual incremental search command C-s works in IMAIL, but it searches only within the current message. The purpose of M-s is to search for another message. It reads a string nonincrementally, then searches starting at the beginning of the following message for a match. It then selects that message. If string is empty, M-s reuses the string used the previous time.

To search backward in the folder for another message, give M-s a negative argument. In IMAIL you can do this with - M-s.

It is also possible to search for a message based on flags. See Flags.

To find the next message with the same subject as the current message, use C-c C-n (imail-next-same-subject). This is useful for following the thread of an email conversation. C-c C-p (imail-previous-same-subject) finds the previous message with the same subject.

To move to a message specified by absolute message number, use j (imail-select-message) with the message number as argument. With no argument, j selects the first message. < (imail-first-message) also selects the first message. > (imail-last-message) selects the last message. M-u selects the first unseen message (imail-first-unseen-message).

4.2 Deleting Messages

When you no longer need to keep a message, you can delete it. This flags it as ignorable, and some IMAIL commands pretend it is no longer present; but it still has its place in the IMAIL folder, and still has its message number.

Expunging the IMAIL folder actually removes the deleted messages. The remaining messages are renumbered consecutively. Expunging is the only action that changes the message number of any message.

d

Delete the current message, and move to the next nondeleted message (imail-delete-forward).

C-d

Delete the current message, and move to the previous nondeleted message (imail-delete-backward).

u

Undelete the current message, or move back to a deleted message and undelete it (imail-undelete-previous-message).

x

Expunge the IMAIL folder (imail-expunge).

There are two IMAIL commands for deleting messages. Both delete the current message and select another message. d (imail-delete-forward) moves to the following message, skipping messages already deleted, while C-d (imail-delete-backward) moves to the previous nondeleted message. If there is no nondeleted message to move to in the specified direction, the message that was just deleted remains current. A numeric argument to either command reverses the direction of motion after deletion.

To make all the deleted messages finally vanish from the IMAIL folder, type x (imail-expunge). Until you do this, you can still undelete the deleted messages. The undeletion command, u (imail-undelete-previous-message), is designed to cancel the effect of a d command in most cases. It undeletes the current message if the current message is deleted. Otherwise it moves backward to previous messages until a deleted message is found, and undeletes that message.

Because imail-expunge irreversibly deletes mail, IMAIL normally requires confirmation before it performs the expunge. This confirmation is controlled by the value of the variable imail-expunge-confirmation, which is a list of symbols. There are two independent behaviors controlled by this: whether to prompt, and whether to show the messages being expunged. If the list contains the symbol verbose (the default), the user is prompted for a yes-or-no style confirmation; if the list contains the symbol brief, the user is prompted for a y-or-n style confirmation; if neither of these symbols is present, no confirmation is done. If the list contains the symbol show-messages, a window is popped up showing the messages to be expunged; otherwise the list is not shown.

You can usually undo a d with a u because the u moves back to and undeletes the message that the d deleted. But this does not work when the d skips a few already-deleted messages that follow the message being deleted; then the u command undeletes the last of the messages that were skipped. There is no clean way to avoid this problem. However, by repeating the u command, you can eventually get back to the message that you intend to undelete. You can also select a particular deleted message with the M-p command, then type u to undelete it.

A deleted message has the ‘deleted’ flag, and as a result ‘deleted’ appears in the mode line when the current message is deleted. In fact, deleting or undeleting a message is nothing more than adding or removing this flag. See Flags.

4.3 Multiple Folders

IMAIL operates by default on your primary folder, which is the folder named ‘inbox’ on your IMAP server. Your incoming mail is placed in that folder by your system’s mail-delivery software. Whenever it has an open connection to the server, IMAIL notices new mail and brings it to your attention by modifying the Edwin mode line.

You can specify a different folder to be your primary folder by modifying one or more of IMAIL’s variables. The simplest way to do this is to change the variable imail-primary-folder to contain the URL of the folder that you wish to be your primary folder. Normally imail-primary-folder is #f, in which case the primary folder has the form

imap://user-id@server/mailbox

where user-id is the value of the variable imail-default-user-id, server is the value of imail-default-imap-server, and mailbox is the value of imail-default-imap-mailbox. imail-default-user-id may be #f meaning to use the value of ‘(current-user-name)’.

In addition to the primary folder, you can also have other folders and edit them with IMAIL. You can move messages into them with explicit IMAIL commands.⁸

One major difference between a file-based mail reader like Rmail and an IMAP mail reader like IMAIL is that file-based mail readers do not need to provide commands to manipulate mail files (as opposed to mail messages). This is because ordinary file-system commands already provide the ability to copy, delete, and rename such files. This isn’t the case for IMAP mail readers. Consequently IMAIL provides a basic set of commands for manipulating folders, as well as a Dired-like folder browser.

• Simple Folder Commands
• The Folder Browser

imap://localhost/inbox/
-----------------------
  + debian/
  + family
  + gnu/
  + ham/
  + hp-laptops/
  + linux/
  + misc/
  + mit/
  + music/
  + purchases
  + scheme/
  + software/
  + sysadmin
  + vendors/
  + vlsi

imap://localhost/inbox/
-----------------------
  - debian/
      + bugs
      + maintainer
      + misc
  + family
  + gnu/
  + ham/
  + hp-laptops/
  + linux/
  + misc/
  + mit/
  + music/
  + purchases
  + scheme/
  + software/
  + sysadmin
  + vendors/
  + vlsi

4.4 MIME Support

The Multipurpose Internet Mail Extensions (MIME) define a standard means for structuring mail messages. MIME permits a message to have multiple parts, each of which is called an entity. It also provides a way to associate type information with each entity. For example, an ordinary text message has type ‘text/plain’, HTML has type ‘text/html’, and a JPEG image has type ‘image/jpeg’. Additionally, MIME entities may be annotated to indicate whether they should be shown in-line, or whether they are attachments that should be shown only upon further user action.

IMAIL provides simple support for MIME messages. MIME attachments are shown in the IMAIL buffer by special abbreviations. You can write an attachment to a file. Multipart MIME structures are recognized and displayed in a clean format that suppresses unnecessary clutter. And MIME encodings such as quoted-printable and base64 are automatically decoded prior to displaying the message or saving the attachment.

End-user formatting of MIME messages is a complex process, partly because these messages can be arbitrarily complex in their internal structure. IMAIL provides several variables that give you some control over the formatting prcess.

Many MIME messages have multiple parts; for example, a message with an attachment normally contains at least two parts: the message text and the attachment. IMAIL separates the different parts of a MIME message with specially-formatted lines. There are several styles of separator lines available, selected by changing the value of the variable imail-mime-boundary-style. The default value of simple means to use long lines of hyphen characters as the separator lines. A value of sgml means use long lines of hyphens that are wrapped with ‘<!--’ and ‘-->’, which makes them valid SGML comments. A value of original means to use the original MIME boundaries, which have certain useful syntactic properties but are not as visually distinctive.

MIME also specifies a particular kind of multipart message, of type ‘multipart/alternative’, in which the parts are different representations of the same message. A typical example of this is a mailer that sends both plain text and HTML versions of the message text. Normally IMAIL shows only the simplest of these parts (which is almost always plain text) and suppresses the alternatives. However, if you set the variable imail-mime-show-alternatives to #t, IMAIL will show these alternative forms as attachments.

Another kind of multipart MIME message is the digest message, which has type ‘multipart/digest’. Digest messages are normally used by high-volume mailing lists to reduce the number of messages sent to the end user; instead the user receives one message containing all of the messages from that list in a particular time period, usually a day. IMAIL can present MIME digest messages in one of two formats. The default format is to show all of the component messages of the digest as attachments. This is particularly useful for large digests that you will only read a few messages from, since you can scan the digest contents for interesting messages without downloading all of the messages in the digest. In the alternative format, selected by setting imail-mime-collapse-digest to #f, the component messages of a digest are all shown inline.

As a general rule, any MIME entity that contains non-textual information is displayed as an attachment. Attachments are normally shown as specially-formatted abbreviations. Here is an example:

<imail-part
    name="foo.doc"
    type="application/msword"
    length="55499"
    />

This shows various things about the attachment, including its (optional) name, its MIME type, and the length of the attachment in bytes. (The length is computed on the encoded form of the attachment, and is generally slightly larger than the decoded length.)

IMAIL uses somewhat more complicated rules for deciding when a MIME entity is displayed in this abbreviated format, and when it is expanded in line. In general, all non-text entities are abbreviated. Additionally, if a text entity is given a MIME disposition of ‘attachment’, if the character set of the entity is unknown, if the encoding type is unknown, or if the subtype is unknown, it is abbreviated.

Two variables control the abbreviation of text entities. imail-known-mime-charsets is a list of regular expressions that specify the known character sets; by default it specifies US-ASCII, the ISO 8859 character sets, and some random but commonly-seen Microsoft Windows character sets. The variable imail-inline-mime-text-subtypes contains a list of symbols, each of which is the name of a text subtype that should be shown in line. For example, if the symbol html is in this list, then MIME parts of type text/html are shown in-line. Text subtypes not appearing in this list are abbreviated as attachments.

Here are IMAIL’s MIME-specific commands:

C-o

Save a MIME attachment to a file (imail-save-attachment).

w

Save an arbitrary MIME entity (message part) to a file (imail-save-mime-entity).

C-c C-t C-e

Toggle a MIME entity between its formatted and raw forms (imail-toggle-mime-entity).

The primary MIME command is C-o (imail-save-attachment), which saves a single attachment to a file. If point is on an attachment, that is the attachment to be saved, otherwise IMAIL prompts for an attachment by name. If a prefix argument is specified, prompting is performed even if point is on an attachment. Once the attachment is determined, IMAIL prompts for the name of a file to save the attachment to. The filename is initialized from the name specified by the attachment, if any. The directory of the filename is initialized to the directory in which the last attachment was saved, or the user’s home directory if no attachments have previously been saved.

If you want to save attachments to a specific directory, change the variable imail-mime-attachment-directory to contain the name of that directory.

The command w (imail-save-mime-entity) is similar to imail-save-attachment except that it will save any MIME entity, not just an attachment. For example, this allows you to save the message text. This command saves the entity that point is on; if point is not on any entity, an error is signalled. If the entity is encoded, e.g. with quoted-printable or base64 encoding, it is decoded before it is saved. If the entity is text, it is written to the file in text mode (relevant only under Windows); otherwise it is written in binary mode.

A simpler way to save a MIME entity is to point at the entity with the mouse and click the right button (imail-mouse-save-mime-entity). This works the same way as imail-save-mime-entity except that the entity is selected by the mouse instead of point.

The command C-c C-t C-e (imail-toggle-mime-entity) is similar to imail-save-mime-entity, except that instead of saving the entity to a file, it toggles whether the entity is shown in-line or in abbreviated form. A common situation in which this is useful is when the text of a message is in an unknown character set. In this case, IMAIL by default shows the text in abbreviated form; use C-t to expand it in place.

4.5 Flags

Each message can have various flags assigned to it as a means of classification. Each flag has a name; different names are different flags. Any given flag is either present or absent on a particular message. A few flag names have standard meanings and are given to messages automatically by IMAIL when appropriate. All other flags are assigned only by users.

a flag RET

Assign the flag flag to the current message (imail-add-flag).

k flag RET

Remove the flag flag from the current message (imail-kill-flag).

C-M-n flags RET

Move to the next message that has one of the flags flags (imail-next-flagged-message).

C-M-p flags RET

Move to the previous message that has one of the flags flags (imail-previous-flagged-message).

C-M-l flags RET

Make a summary of all messages containing any of the flags flags (imail-summary-by-flags).

The a (imail-add-flag) and k (imail-kill-flag) commands allow you to assign or remove any flag on the current message.

Once you have given messages flags to classify them as you wish, there are two ways to use the flags: in moving and in summaries.

The command C-M-n flags RET (imail-next-flagged-message) moves to the next message that has one of the flags flags. The argument flags specifies one or more flag names, separated by commas. C-M-p (imail-previous-flagged-message) is similar, but moves backwards to previous messages. A numeric argument to either command serves as a repeat count.

The command C-M-l flags RET (imail-summary-by-flags) displays a summary containing only the messages that have at least one of a specified set of flags. The argument flags is one or more flag names, separated by commas. See Summaries, for information on summaries.

If the flags argument to C-M-n, C-M-p or C-M-l is empty, it means to use the last set of flags specified for any of these commands.

Some flags such as ‘deleted’ and ‘filed’ have built-in meanings and are assigned to or removed from messages automatically at appropriate times. Here is a list of built-in flags:

‘seen’

Means the message has been selected, implying that the user has seen it. Assigned to a message when it is selected by the user. When you start IMAIL, it initially shows the first message that lacks this flag.

‘deleted’

Means the message is deleted. Assigned by deletion commands and removed by undeletion commands (see Deleting Messages).

‘filed’

Means the message has been copied to another folder. Assigned by the message-copying commands (see Multiple Folders).

‘answered’

Means you have mailed an answer to the message. Assigned by the r command (imail-reply). See Sending Replies.

‘forwarded’

Means you have forwarded the message. Assigned by the f command (imail-forward). See Sending Replies.

‘resent’

Means you have resent the message. Assigned by the command C-u f (imail-resend). See Sending Replies.

All other flags are assigned or removed only by the user, and have no standard meaning.

4.6 Sending Replies

IMAIL has several commands that use Mail mode to send outgoing mail. What this section documents are the special commands of IMAIL for entering Mail mode. Note that the usual keys for sending mail—C-x m, C-x 4 m, and C-x 5 m—are available in IMAIL mode and work just as they usually do.

m

Send a message (imail-mail).

c

Continue editing the already started outgoing message (imail-continue).

r

Send a reply to the current IMAIL message (imail-reply).

f

Forward the current message to other users (imail-forward).

C-u f

Resend the current message to other users (imail-resend).

The most common reason to send a message while in IMAIL is to reply to the message you are reading. To do this, type r (imail-reply). This displays the ‘*mail*’ buffer in another window, much like C-x 4 m, but preinitializes the ‘Subject’, ‘To’, ‘CC’ and ‘In-reply-to’ header fields based on the message you are replying to. The ‘To’ field starts out as the address of the person who sent the message you received, and the ‘CC’ field starts out with all the other recipients of that message.

You can exclude certain recipients from being placed automatically in the ‘CC’, using the variable imail-dont-reply-to-names. Its value should be a regular expression (as a string); any recipient that the regular expression matches is excluded from the ‘CC’ field. The default value matches your own name, and any name starting with ‘info-’ (the value of the variable imail-default-dont-reply-to-names). (Those names are excluded because there is a convention of using them for large mailing lists to broadcast announcements.)

To omit the ‘CC’ field completely for a particular reply, enter the reply command with a numeric argument: C-u r or 1 r.

By default, the ‘Subject’ field of a reply is initialized to the contents of the ‘Subject’ field of the message being replied to. However, if the variable imail-reply-with-re is set to #t, then the reply subject will be prefixed with ‘Re:’.

Once the ‘*mail*’ buffer has been initialized, editing and sending the mail goes as usual. You can edit the presupplied header fields if they are not right for you. You can also use the commands of Mail mode, including C-c C-y which yanks in the message that you are replying to. You can switch to the IMAIL buffer, select a different message there, switch back, and yank the new current message.

Another frequent reason to send mail in IMAIL is to forward the current message to other users. f (imail-forward) makes this easy by preinitializing the ‘*mail*’ buffer with the current message as a MIME attachment, and a subject designating a forwarded message. All you have to do is fill in the recipients and send. When you forward a message, recipients get a message which is “from” you, and which has the original message in its contents.

By default, forwarded messages are sent as MIME attachments, which allows MIME-aware mail readers to recognize that the attachment is a mail message and to specially present it. However, this means that such forwarded messages appear more complex when viewed in mail readers that do not understand MIME. IMAIL deliberately minimizes the amount of encoding overhead used for MIME-forwarded messages, but some people prefer not to use MIME at all. For that reason, IMAIL allows you to turn off this feature, so that forwarded messages are included in the main body of the message (as Rmail does). To do this, set the variable imail-forward-using-mime to #f.

Normally, when IMAIL forwards a message, it sends only a few of the message’s header fields. In particular, it sends only those header fields that you see when viewing the message in IMAIL. Sometimes it is desirable to send all of the message’s header fields; IMAIL provides two ways to do this. First, if you want to send all of the header fields for a particular message, use imail-forward with a negative argument, like this: - f. Alternatively, you can set the variable imail-forward-all-headers to #t, which will cause all forwarded messages to retain all of their header fields.

Resending is an alternative similar to forwarding; the difference is that resending sends a message that is “from” the original sender, just as it reached you—with a few added header fields ‘Resent-from’ and ‘Resent-to’ to indicate that it came via you. To resend a message in IMAIL, use C-u f. (f runs imail-forward, which is programmed to invoke imail-resend if you provide a numeric argument.)

The m (imail-mail) command is used to start editing an outgoing message that is not a reply. It leaves the header fields empty. Its only difference from C-x 4 m is that it makes the IMAIL buffer accessible for C-c C-y, just as r does. Thus, m can be used to reply to or forward a message.

The c (imail-continue) command resumes editing the ‘*mail*’ buffer, to finish editing an outgoing message you were already composing, or to alter a message you have sent.

4.7 Message Display

IMAIL provides several variables and commands to give you control over how messages are formatted in the message buffer.

By default, IMAIL automatically wraps long lines at the right margin. It uses adaptive fill⁹ to do the wrapping, which means that common prefixes such as ‘>’ and ‘Chris>’ will be automatically copied down with the wrapped line. Generally, this wrapping makes messages easier to read. Specifically, it is important for messages sent by clients that use “soft” line breaks, because such clients expect the mail reader to wrap lines. However, if you’d rather not have IMAIL do this for you, you can disable wrapping by setting the variable imail-auto-wrap to #f.

Another feature of IMAIL is that it filters message headers, showing you only the most relevant ones. There are two variables that control how this is done, and a command that can override the filtering. The variable imail-kept-headers contains a list of regular expressions that are matched against message-header names (the name is everything to the left of the colon, e.g. ‘From’ in ‘From: cph’). If imail-kept-headers is a non-empty list, then only the headers matching those regular expressions are shown. Furthermore, the shown headers will be in the same order as the regular expressions.

If imail-kept-headers is an empty list, then all of the message headers are shown, except those matching the regular expression that is the value of the variable imail-ignored-headers. By default, the value of imail-ignored-headers contains some common uninteresting header names; this expression is identical to the default used by Rmail. Note that imail-ignored-headers is a single regular expression, while imail-kept-headers is a list of regular expressions. This is because imail-ignored-headers is meant to be an exact analog of the Rmail variable rmail-ignored-headers.

Regardless of how the message-header filtering is done, you can toggle between viewing the filtered headers and the unfiltered headers using the t command (imail-toggle-header). If filtered headers are shown, this command replaces them with unfiltered headers, and vice versa.

As you can see, IMAIL performs extensive transformation of a mail message before presenting it to you: MIME formatting, line wrapping, and header filtering. Sometimes, it’s desirable to see the original message, exactly as it was received, without any formatting at all. The command C-c C-t C-m toggles the entire message between a formatted view and a raw view. This should be used with care, as a message with a large attachment might not fit in memory in its raw form.

4.8 Summaries

A summary is a buffer containing one line per message to give you an overview of the mail in an IMAIL folder. Each line shows the message number, the sender, the flags, and the subject. Almost all IMAIL commands are valid in the summary buffer also; these apply to the message described by the current line of the summary. Moving point in the summary buffer selects messages as you move to their summary lines.

A summary buffer applies to a single IMAIL folder only; if you are editing multiple IMAIL folders, each one can have its own summary buffer. The summary buffer name is made by appending ‘-summary’ to the IMAIL buffer’s name. Normally only one summary buffer is displayed at a time.

• Making Summaries
• Editing in Summaries

4.9 Sorting Messages

IMAIL provides several commands that change the order of messages within a folder. These commands are closely modelled on those of Rmail. Note that these commands don’t modify the folder itself; they only modify the way that the folder behaves. This means that if a folder buffer is deleted, the sort order associated with that buffer is deleted too.

C-c C-s C-v ¶

Sort messages of current IMAIL folder by arrival time (imail-sort-by-arrival). This is the default; this sort undoes any other sorting on the folder.

C-c C-s C-d ¶

Sort messages of current IMAIL folder by date (imail-sort-by-date).

C-c C-s C-s ¶

Sort messages of current IMAIL folder by subject (imail-sort-by-subject).

C-c C-s C-a ¶

Sort messages of current IMAIL folder by author’s name (imail-sort-by-author).

C-c C-s C-r ¶

Sort messages of current IMAIL folder by recipient’s names (imail-sort-by-recipient).

C-c C-s C-c ¶

Sort messages of current IMAIL folder by the name of the other correspondent (imail-sort-by-correspondent).

The IMAIL sort commands perform a stable sort: if there is no reason to prefer either one of two messages, their order remains unchanged. You can use this to sort by more than one criterion. For example, if you use imail-sort-by-date and then imail-sort-by-author, messages from the same author appear in order by date.

With a numeric argument, all these commands reverse the order of comparison. This means they sort messages from newest to oldest, from biggest to smallest, or in reverse alphabetical order.

4.10 Other Commands

This section documents a handful of commands and variables that don’t fit into any of the other documentation categories.

q

Quit out of IMAIL (imail-quit). This closes all open IMAP connections and buries all IMAIL buffers. With prefix argument, only affects the current IMAIL buffer, leaving any other IMAIL buffers alone.

M-d

Disconnect from the IMAP server (imail-disconnect).

b

Bury the IMAIL buffer (imail-bury).

s

Save changes in the current folder to disk (imail-save-folder).

When you are finished reading mail in a folder, use the q command (imail-quit). This command closes the folder, then buries the buffer. Closing a folder has different effects, depending on the type of folder. Closing an IMAP folder causes IMAIL to disconnect from the IMAP server (go offline). Closing a file folder saves any changes out to the corresponding file. In both cases, internal data structures may be dropped, requiring them to be rebuilt, should the folder later be re-opened. In no case are any changes made to the folder’s contents; in particular, deleted messages are not expunged.

On IMAP folders, the q command is equivalent to M-d b. On file folders, the q command is equivalent to s b.

The M-d command (imail-disconnect) disconnects IMAIL from the IMAP server (goes offline). This has no effect on file folders.

The b command (imail-bury) buries the selected IMAIL buffer. Burying a buffer means moving it to the bottom of the buffer list and selecting another buffer from the top of the list. This is similar to the command bury-buffer, except that any summary buffer associated with this buffer is also buried, and if a window was created to hold the summary buffer, it is deleted.

The s command (imail-save-folder) saves out any changes to the selected IMAIL folder. For file folders, this means writing the folder back out to its file. For IMAP folders, this no effect. In no case are any changes made to the folder’s contents; in particular, deleted messages are not expunged.

IMAIL normally caches IMAP message bodies in memory in order to increase performance. The variable imail-body-cache-limit gives you some control over how this caching is done. imail-body-cache-limit is normally set to a positive integer, meaning that any message body or in-line MIME entity whose size in bytes is less than this number is cached. However, caching can be entirely disabled by setting imail-body-cache-limit to #f, or made unconditional by setting it to #t.

Another thing that IMAIL caches is IMAP passwords. This is done so that you don’t have to keep typing your password whenever you connect to a new IMAP folder. However, this is also a security risk, because the password is kept in Scheme’s memory. The variable imail-pass-phrase-retention-time says how long passwords are cached, in minutes. Normally this is set to 30 minutes, but if you are paranoid you can set it to zero to disable password caching altogether. Scheme keeps track of the use of each password, and deletes its copy of the password when it has expired. Additionally, Scheme stores passwords in an obscured form, to prevent them being seen during casual browsing through memory structures, but this does not provide any protection against a deliberate attempt to find the password.