Provided by: exmh_2.9.0-3_all bug

NAME

       exmh - An introduction to the exmh mail user interface.

INTRODUCTION

       This  man  page  provides  a quick tour through some of the basic features of exmh version
       2.0, which provides a graphical user interface to the MH mail system.

       After you read this tutorial you should be able to use exmh  for  your  basic  daily  mail
       reading  needs.   You  will  learn  how  to  send mail, read mail, manage your messages in
       folders, and adjust some of the exmh features by means of its Preferences user interface.

       There is much more documentation available on-line through HTML pages  that  are  viewable
       from  within  exmh.   In  particular.   exmh-use provides information about using the more
       advanced features of exmh.  If you are already an experienced email user, you may want  to
       just  read the GETTING STARTED section here and then skip to the exmh-use man page.  exmh-
       custom describes how to customize exmh to suit your needs.  exmh-ref lists each button and
       menu  entry  in exmh and explains what they do.  If you are an experienced exmh user, this
       may be the most useful man page for you.

       A cleaned up version of these man pages appear in the 3rd edition of  the  book  by  Jerry
       Peek,  MH  &  xmh:  email  for  users  and  programmers,  which is published by O'Reilly &
       Associates.

       Web versions of the documentation can also be found at

       http://www.beedub.com/exmh/

GETTING STARTED

       If you are already an MH or xmh user, you can start with the examples given in this  tour.
       If  you  are a new user, exmh will set up your basic MH environment.  This includes a Mail
       directory which will have one subdirectory for each mail folder, plus several  files  that
       MH  mail  uses  for  its  own  purposes.   You also get a ~/.mh_profile file that has user
       settings for MH and exmh.

       Exmh uses the regular MH programs to manipulate your  mail  folders  and  messages.   This
       means  it  is  compatible  with command-line use of MH programs, and its actions should be
       familiar if you are an experienced MH user.  If you are a new MH user, then the details of
       running  MH  programs  is  hidden behind the graphical interface.  The MH programs used by
       exmh are described towards the end of this man page.

       When you run exmh for the first time it checks a  few  things  in  your  MH  profile.   In
       particular,  it  depends  on  the Draft-Folder and Unseen-Sequence profile components.  If
       these profile components are not present, a dialog appears and exmh can set  them  up  for
       you.   If  you  do  not  let  exmh create them nor set them up by hand, exmh will not work
       properly.  These profile entries are described in the exmh-ref man page.

       Exmh has been designed to be very flexible, although it will work just fine  "out  of  the
       box".  The Preference package used to adjust some of the settings in exmh is introduced in
       this man page, and some of the important settings are described  here.   A  more  complete
       guide to customizing exmh is given in the exmh-custom man page.

RUNNING EXMH

       The  command  to  start  exmh  looks like this: exmh -display hostname:0 & If your DISPLAY
       environment variable is set up properly, then the -display argument is not needed, and the
       command  is  even simpler.  You do not need to specify a -geometry argument, although exmh
       supports one.  Instead, simply position and size the window  using  your  window  manager.
       When  exmh  quits,  it saves the geometry information so you don't have to worry about it.
       It does this with all its top level windows, so you can adjust  their  position  once  and
       then  forget  about it.  There are more command line options described in the exmh-ref man
       page.

       You can add the exmh command to your startup X environment by editing  your  startup  file
       (like  .xsession).  You might also want to add it to the main menu of your window manager.
       The details about this vary from X system to X system, so ask your local X guru for  help.
       Exmh  also  supports  the  window manager session protocol, which means that session-smart
       window managers will automatically start exmh for you if you quit X when exmh is running.

THE EXMH DISPLAY

       This section describes the main parts of the exmh display.  It probably makes sense to run
       exmh  at  this  point  so  you  can  follow along.  There are three sets of buttons in the
       interface, and three main subwindows.

       Main Buttons.  Along the top of the window is a set of buttons and  menus  that  apply  to
       exmh  itself.  Quit, for example, quits exmh.  The Help button pops up a menu, and you can
       select the entries there to get more on-line information about exmh.  Use the  left  mouse
       button  to  select  the  buttons  and menus.  A button will change its appearance when you
       press it, and it will be invoked when you release the mouse over the button.  If you slide
       the mouse off the button before releasing it, nothing happens.

       Folder Display.  Below the main buttons is the folder display subwindow.  It has a special
       button for each of your top-level folders, and these are called folder labels.  As  a  new
       user  you  will  see two folder labels, one for inbox and drafts.  The inbox folder is for
       your new messages, and the drafts folder is for messages you are  writing.   If  you  have
       used  MH  (or  xmh)  before,  then you may have many more folders that will appear in this
       display.  The mouse bindings for folder labels are explained in  the  exmh-use  man  page.
       The  Color Legend from the Help menu also tells you how the folder labels respond to mouse
       clicks.

       Folder Cache.  A second folder display called the folder cache may appear under  the  main
       folder display.  This shows the folder labels for recently used folders.  If you only have
       a few folders this wastes screen real estate.  The PREFERENCES section  near  the  end  of
       this  man page explains how to turn this off via the Folder Cache preferences setting.  If
       you are a first-time exmh user, Exmh tries to guess if you need this display based on  the
       number of folders and nested folders you have.

       Folder  Buttons.   The middle set of buttons is for operations that apply to folders.  For
       example, you can create a new folder  with  the  New  button  here.   The  More...  button
       displays  a  popup  menu  with  several more operations you can apply to folders.  Some of
       these buttons will be introduced in this man page.  All of these  buttons  and  menus  are
       explained in detail in the exmh-ref man page.

       To  the  left  of  the  folder  buttons,  summary  information about the current folder is
       displayed.

       Table of Contents.  The middle subwindow of the display shows a summary of the messages in
       the  folder.   It  shows  the  message number, the date of the message, the subject of the
       message, and, space permitting, the first few words of the message.  Left click on a  line
       in  the  table  of contents to view the corresponding message.  The mouse bindings for the
       table of contents are described in more detail in the exmh-use man page.

       MH experts: The display in this window comes from both the  MH  scan  program  or  MH  inc
       programs, so it is affected by the form specification used by these programs.

       Color  and  Monochrome  Highlights.  Both the folder display and table of contents windows
       use highlights to give you visual clues about the state of  messages  and  folders.   Your
       unread  messages  are  highlighted  in  the table of contents and the folders that contain
       unread message are highlighted in the folder display.  Pull down the main  Help  menu  and
       select Color Legend to display a key to the highlights for your display.  The highlighting
       is covered in more detail later in the exmh-use man page.  The exmh-custom man page  tells
       how you can control the highlighting yourself.

       Status  Line.   Just  below the table of contents is the status line.  This has two parts.
       The left part shows the name of the folder and the message number for the current message,
       if  any.   The  right  part  gives feedback about what exmh is doing.  After it displays a
       message, the Subject component is displayed there.

       Subwindow Resize Diamond.  The black diamond to the right of the status line  is  used  to
       change  the size of the internal windows.  Press the first mouse button on this target and
       a horizontal line appears.  Drag it up and down to adjust the window sizes.  Try  dragging
       it  all  the  way  to the top and bottom of the exmh window to see how the mode changes to
       adjust different windows.

       Message Buttons The bottom row of buttons are for operations that  apply  to  the  current
       message.  Several of these operations will be introduced in this man page.  The right hand
       button labeled More... brings up a menu with several more advanced message operations.

       Hint: Many of these message operations have keyboard shortcuts that make it  easy  to  use
       exmh  with  your hands on the keyboard.  Some of the short-cuts are introduced in this man
       page, and all of them are listed in the exmh-use man page.

       Message Display.  The bottom subwindow displays the current message, if any.  Some of  the
       less interesting mail headers start out scrolled off the top of this window.

SENDING MAIL

       A  good  way  to test things out is to send a message to yourself.  Here are the steps you
       take to do that:

       1.  Click the Send button, which is in the Message buttons in the  bottom  group.   A  new
       window  will open that contains the template for your message.  The built-in editor, which
       is called sedit, will start out with the insert cursor positioned at the end of the  first
       empty  header  line.   Enter your user name after the To: header.  If you want to send the
       message to more than one person, use a comma to separate the names.

       2.  Position the insert cursor on the next header line.  You can do this a  few  different
       ways.   The most direct way is to click the left mouse button where you want the cursor to
       be.  There are keyboard shortcuts, too.  If you press <Tab> the editor will  take  you  to
       the  end  of  the  next  header  line.  You can also use the arrow keys or some emacs-like
       bindings to move the cursor.  <Control-n> goes to the next  line,  <Control-f>  moves  the
       cursor  forward  a  character.   <Control-p> moves up a line, and <Control-b> moves back a
       character.  The Simple Edit menu entry shows you all the keybindings.

       3.  The next header is the Cc: line.  People listed in the Cc: line get a  "courtesy"  (or
       "carbon")  copy  of  the  message.  By convention, the message is primarily for the people
       listed in the To: component, and the people in the Cc: component are getting  the  message
       "for information."  In this case, you can leave the Cc: component empty.

       Move  the insert cursor to the Subject: line and enter a Subject.  The people that receive
       your message will get an idea of what the message is about from the  subject,  so  take  a
       moment  to  think  of  a  good one.  For this test, you can type something like "exmh test
       message".

       4.  Make sure the headers are OK.  In particular, make sure there are no  blank  lines  in
       the  headers.   The  mail  system  treats a blank line as meaning "end-of-headers", so you
       don't want to prematurely end the header section.  If you have a blank line, position  the
       insert cursor on it and use Backspace to remove the empty line.

       Position  the cursor at the start of the message body.  You can use the mouse for this, or
       you can press <Tab> twice quickly and the editor will position the cursor correctly.  When
       using the default MH message templates, this will be right after the line of all dashes.

       5.   Type  in  your  message.   When  you  type  in  a  long  message, the lines will wrap
       automatically at word boundaries.  To get a blank line  for  paragraph  boundaries,  press
       <Return>.  The built-in editor supports several editing commands that are based on the GNU
       emacs key bindings.  If you select the Simple Edit menu  entry  under  the  main  Bindings
       menu, you will bring up a dialog that lets you view and edit the key bindings.

       6.  If you are happy with the message, you send it by pressing the Send button at the top-
       right corner of the window.  The Send button will turn grey, and the window will disappear
       once the message has been sent successfully.

       If  you  do  not want to send the message, press the Abort button instead.  If you want to
       save the message draft and continue to work on  it  later,  press  the  Save&Quit  button.
       Working on a saved draft message is described in the exmh-use man page.

       Send yourself a few messages, or have a friend send you a few test messages.  You will use
       these test messages to practice moving around in a folder and deleting messages.  Make one
       of the messages pretty long so you can practice scrolling through it.

       Finally,  try  sending  mh-mime-sample@online.ora.com a message.  This addresses a program
       that will return a MIME message to you.  Just put  this  address  in  the  To  field  with
       anything as the message body and subject.  Reading this message will be described below.

MOUSING AROUND

       The  selection is dragged out with the left mouse button.  You can modify the selection by
       holding the Shift key while pressing the left  button.   A  double-click  begins  a  word-
       oriented  selection,  and  a triple-click begins a line-oriented selection.  If you drag a
       selection off the bottom or top of a window the text will be  scrolled  automatically  and
       the selection will be extended.

       Paste  is  done  with  the middle mouse button.  The current insert point is used, not the
       point at which you middle-click.  If you drag the middle mouse button, then the window  is
       scrolled  instead  as  described  below.   There is also a key-binding for paste, which is
       <Control-y>.  Use <Control-w> or the <Delete> key to delete the selection.

       The middle mouse button is used for "drag-scrolling".  To scroll, simply press the  middle
       mouse  button  over the text and drag the text.  If you press the Shift key, the scrolling
       is faster.  Drag-scrolling works in the text widgets, for vertical scrolling, and the one-
       line  entry  widgets,  for horizontal scrolling.  The text widgets are used to display the
       folder contents and the current message.  The entry widgets are used in various dialogs in
       order to enter values.  You can change the scrolling button to the right button or to only
       work with shift-middle.  Set this up in the Simple Edit Bindings... dialog.

       Buttons and menus are also sensitive to which mouse button  is  pressed.   Only  the  left
       button  activates a button, and it is the <ButtonRelease> event that is important.  If you
       accidentally move the mouse off of the button as you  release  it,  nothing  will  happen.
       Don't worry, the wrong button will not be invoked.

       Press  the left button over a menu button to  pull down a menu.  Most of the menus in exmh
       are distinguished with a "..."  in their label, e.g. "More...".  The  menu  will  go  away
       when  the button is released.  Release the mouse button off the menu if you do not want to
       invoke any menu item.  (In some versions of Tk, the middle button will  "tear  off"  a  Tk
       menu.   This  is  quite  handy if you use the menu often.  To get the menu to go away, you
       must click the left button over the menu button.  This will reattach the menu to the  menu
       button,  and another left click will make the menu go away.  In the latest versions of Tk,
       the first menu entry is a dashed line that invokes this tear-off operation.)

GETTING NEW MAIL

       By now you should have some new mail waiting.  Press the Inc button from the middle set of
       buttons  that  do  Folder  operations.  This will transfer messages from your system spool
       file into your inbox folder.  You will hear an audible cue if there was new mail, and  the
       table of contents will be updated to reflect the new messages in your inbox.  New messages
       will be underlined (on a monochrome screen), or blue (on a color screen), to indicate that
       you have not read them yet.

       To  view  the  new  message, click on its line in the table of contents, or press the Next
       button in the bottom group of buttons.  The  message  will  be  displayed  in  the  bottom
       subwindow,  and  the line in the table of contents will be highlighted to remind you which
       message is being displayed.

       To view the next message, click the Next button.  The keyboard shortcut for  this  is  the
       'n' key.

       The  view  the previous message, click the Prev button.  The keyboard shortcut for this is
       the 'p' key.

       Scrolling through messages.  If you get a message that is too long to fit into the message
       window,  then  the  scrollbar  will  change  its  appearance  to indicate how much text is
       displayed.  The scrollbar is Motif-like.  You can click on the arrows at either end to  go
       up and down one line.  If you click above or below the elevator box you go up and down one
       page.  You can drag the elevator box to scroll, too.

       You can also scroll text windows in exmh by dragging with the middle mouse button.   Press
       the  middle  button over the text area, not the scrollbar, and hold it down while you move
       the mouse up or down.  If you hold the shift key  at  the  same  time,  the  scrolling  is
       faster.  This works in the folder Table of Contents window, too.

       Hint.   The  space  bar  is  a keyboard short-cut that does a combination of scrolling and
       advancing to the next message.  If the message is long, then  space  will  scroll  by  one
       screen.   Once  you are at the end of the message, space will advance to the next message,
       just like the 'n' key.  You can use the BackSpace key to scroll back through a message.

READING MIME MESSAGES

       By  now  you  should  have  also  received  the  sample   MIME   message   from   mh-mime-
       sample@online.ora.com.  The MIME message has three parts to it, and these are numbered and
       labeled in the display.  The first part is a multipart/alternative  content,  which  means
       there  are  a  few  different  ways to view the content.  This is indicated by the message
       under the heading 1. that there are alternative views of the following content.  Exmh will
       go ahead and display what it thinks is the best alternative, and you see the text/enriched
       content displayed in part 1.2.  If you want to see the other alternatives,  then  you  can
       press the right button over section 1 to get a popup menu with some choices.

       The  next  two  parts  are  an  audio clip and a picture in GIF format.  The audio clip is
       handled directly by exmh, and it displays two active text buttons labeled  "Play  attached
       audio"  and  "Save audio file".  Click on either of these with the left mouse button.  The
       part corresponding to the image displays a message about what the type  is,  and  suggests
       that  you  press the right mouse button to display a menu.  You can always press the right
       button to get a MIME menu that has type-specific options for parts of  your  message.   If
       you press the right button over part 2., then the popup menu will offer you these choices:
       Decode part as MIME Save Hello from the author...  View using  mailcap  rule...   Pass  an
       audio  fragment  to metamail...  The first item is a checkbox menu item that lets you view
       the raw content if you want to.  The Save... menu entry displays a file selection  box  so
       you can choose a non-temporary file to store the content.  This same function is available
       through the text button, but not all MIME parts displays buttons like this.  The next  two
       entries  should  result  in  the  same  thing.  They use the mailcap specifications to run
       another program that displays the content.  In the first case, View using mailcap rule...,
       exmh  runs  the  program  directly.   In the other case, Pass to metamail..., the metamail
       program is run first, and it decodes the mailcap  file  and  runs  the  external  program.
       Again, the text button labeled "Play attached audio" also plays the audio.

REPLYING TO MAIL

       Select  one  of  the  messages from your friend that you'd like to answer.  Press the left
       button over the Reply... menu button.  A menu  with  a  few  entries  will  be  displayed.
       Select the Reply to sender menu entry by dragging the mouse down to that entry and letting
       up over it.  The menu entry has a <Key-r> in it, which means that you could also press the
       'r' key to invoke this function.

       This  time the built-in editor will open a window with a message that is partly filled in.
       All the headers are initialized based on the header components from the original  message.
       The built-in editor will automatically position the cursor at the beginning of the message
       body.  You can enter your reply message like you did  with  the  previous  messages.   You
       should  also  double-check  the  header components.  In this case, add yourself to the Cc:
       component so you will get a copy of the reply message.  When you are done, press the  Send
       button in the editor window to send the message.

       There  are  a  number  of  ways to control the format of your reply messages.  The MH repl
       command has several formatting options, and because exmh uses repl to  set  up  the  reply
       message,  you can customize your reply format.  Exmh lets you define several variations on
       reply and add them to the Reply... menu.  This is described in the exmh-custom man page.

       It should not take long for you to get the copy of the reply message.  Wait a minute or so
       and press the Inc button.  The keyboard short-cut for Inc is the 'i' key.

SELECTING MESSAGES

       Before  we  go on to more things you can do with messages, we need to talk about selecting
       multiple messages at once.  Several of the message operations in exmh can operate on a set
       of  messages.   You  can  manually select multiple messages by using the mouse, or you can
       select messages based on their content.

       Using the Mouse.  To select messages with the mouse, press the left button and  then  drag
       out  a  selection.   This will select a contiguous range of messages.  If the messages you
       want to select are not so nicely organized, you can make a disjoint selection  by  holding
       down  the Shift key while making your selection.  This adds new messages to the selection.
       If you shift-click on a message that is already selected, then it becomes unselected.   If
       you  need  to select a lot of messages, simply drag the mouse off the top or bottom of the
       window.  It will be scrolled automatically and the selection will be extended.

SEARCHING

       The Search... menu has several operations for finding messages and finding text  within  a
       message.  There is also a help entry that explains searching in more detail.

       If  you select "Find in message body" or "Find in table of contents" a small search dialog
       appears.  Enter the search string and use the Next or Prev buttons to find the next match.
       When  you  are  searching  over  the  table  of contents, you can select All to select all
       matching messages.

       The other way to search a folder is with "Pick by attributes".  The  MH  pick  program  is
       used  to  search  the  current  folder  for  messages that match mail headers like From or
       Subject.  You can build up boolean expressions among search criteria.  This is a much more
       general search mechanism than the "Find in table of contents" operation.

       Get  started in the Pick dialog by pressing the "Choose pick attribute" button.  A menu of
       attribute types appears, including the Subject, From, To, and Cc header  components.   You
       can  type a regular expression pattern in these entries to search for messages that have a
       matching header component.

       The Before and After attributes are dates.  You can find all messages before  or  after  a
       given  date by using these fields.  You can specify dates as mm/dd/yy.  Be sure to include
       the year.  Dates can also be keywords like "today", "yesterday", "tomorrow", and  any  day
       of the week ("Sunday", "Monday", and so on.)

       The  Search attribute is used to search for something in the body of a message.  This will
       run little slower because pick must read through all of  your  messages,  not  just  their
       headers.

       If  you  select  more than one attribute, pick finds messages that match all the criteria.
       In other words, it does the logical and of the search criteria.  If you want to search for
       this  or  that, then you need to press the Or button in the dialog.  This adds another set
       of fields to the dialog, and pick will search for everything that matches the first set or
       matches the second set.

       The  "Add  to  Sel"  checkbutton  should  be  set before you do the search.  This controls
       whether or not the selected messages are added to any existing selection.

       Finally, use the "Pick" button to do the search.  Once the search has  completed  you  can
       perform  a  few  operations  on  the  selection.   You  can  delete and refile messages as
       described later.  You can also display a new table of  contents  that  only  contains  the
       selected  messages.   Use  the  "New FTOC" button for this.  You can also clear the unseen
       state of the messages with the "Mark Seen" button.

       The "Clear" button resets the fields.

       The two entries in the dialog are used to control MH sequences.  The  only  sequence  exmh
       really  supports well is the "unseen" sequence, although you can define up to 10 sequences
       in each folder.

       If you use New FTOC to get a new scan listing, it would be better if it appeared in a  new
       window,  but  currently  it  replaces  the  table  of  contents.   You can move around and
       manipulate messages in this table of contents.  However, if you do another pick,  it  will
       only find things in this limited table of contents, not the whole folder.  (Yes, this is a
       bug.)  Use the Rescan Folder menu entry in the folder  More...  menu  to  get  a  complete
       folder listing.

FORWARDING MESSAGES

       If  you  want  to send someone a copy of a message or messages that you have received, use
       the Forward message operation.  Select the messages as described in the previous  section,
       then press the Forward button.  The keyboard short-cut for forward is the 'f' key.

       The  message template will have a copy of the selected messages.  You fill in the headers,
       and you can also add a short message before the start of the forwarded messages.  When you
       are done, press Send to forward the messages.

DELETING MESSAGES

       After you have read a message, you might want to remove it to keep your mail folders tidy.
       Exmh uses two steps to remove mail.  In the  first  step  you  mark  a  message  as  being
       deleted.   In  the second step you commit the operations on all marked messages.  It turns
       out that delete just renames your message files.  They will survive until you get  another
       message  by  the  same  number and remove it, too.  In addition, exmh has a "Purge Folder"
       operation that removes these renamed files if they are more than a week old.

       The Delete operation applies to the current message, or you can also  select  a  range  of
       messages by dragging out a selection in the table of contents.  You can delete the current
       message(s) by pressing the Delete button.  The keyboard short-cut is  the  'd'  key.   The
       deleted  message(s)  will  be highlighted after the delete operation so you can easily see
       the state of the message.  On a monochrome screen, a cross hatching will be drawn  through
       the table of contents line for the message.  On a color screen, the table of contents line
       will get a dark grey background.

       After you mark a message for delete, you are automatically advanced to the  next  message.
       This  makes  it  easy  to go through your folder and clean it up.  Click 'd' to delete, or
       click 'n' to leave it alone.

       Hint.  If you are really in a hurry, use 'D' and 'N' as your  keyboard  short-cuts.   This
       prevents  the next message from being displayed, which can be slow for complex multi-media
       messages.

       When you are ready to commit the pending delete actions, press  the  Commit  button.   The
       keyboard shortcut for commit is <Control-Return>.

       If  you  decide  you  do  not  want to delete a message you can unmark it.  Use the Unmark
       (Undo) menu entry that is under the message More... menu.  The unmark operation applies to
       the  current message or messages, so you have to select the messages to unmark first.  The
       keyboard short-cut for unmark is 'u'.

       Hint.  The minus, '-', keyboard shortcut takes you to the previous message, even if it has
       been marked for delete.  Ordinarily the Prev operation, and the 'p' short-cut for it, will
       skip over marked messages.

LEAVING EXMH

       Press the Quit button to leave exmh.  It will take a few moments to close down because  it
       saves  some  state  information  before quitting.  The Quit button will grey out after you
       click it, and you will see a few status messages as it shuts itself down.

PREFERENCES

       Try out the Preferences by turning off the folder cache.  This just takes up display space
       if  you  don't  have  many folders.  If you have lots of nested folders, though, you might
       even want to make this display bigger!

       Click the Preference button, which brings up a dialog that has buttons for several of  the
       modules  that  make  up exmh.  Click on the Folder Cache button to bring up the preference
       items that control the folder cache.  In this case there are just two items: the number of
       lines  of  labels  in  the  cache,  and the names of folders that are always in the cache.
       Click in the first field and backspace over the default value of 1.  Type  in  0  instead,
       and press <Return>.  Voila!  The folder cache disappears.

       If  you  like this setting, press Save on the main Preference dialog and your changes will
       be saved to a file named ~/.exmh-defaults.  Press Reset if you want to undo your  changes.
       You  should  be  a  little careful here, because you are allowed to Dismiss the preference
       dialog without saving.

       Another useful preference item to set is under Background Processing.  You can arrange for
       exmh  to  periodically  run  inc  so your messages are automatically transferred into your
       inbox.  The advantage of doing this is that the folder label highlighting works best  this
       way.   Unfortunately, exmh does not give you any visual clues when mail is only waiting in
       your system spool file.

       More details about the Preferences dialog are given in  the  exmh-use  man  page,  and  an
       overview of the various preference sections is given in the exmh-custom man page..

WHAT IS MH MAIL?

       MH  is  a  collection  of  UNIX programs that store, manipulate, and display your mail. MH
       originated from RAND, and it is now in the public domain.  Exmh uses these programs to  do
       all the hard work, while it concentrates on the user interface.

       You  can  use the MH programs to read your mail.  Run them from the UNIX command line like
       you would cd, ls, cc, or make.  They are useful when you are connecting over a  slow  line
       or  cannot  run  exmh  for  some other reason.  For more details, there are individual man
       pages for each MH program, plus one overview man page called MH.  Below is a short summary
       of the main MH programs used by exmh.

       folder Query or set the current folder.

       inc    Incorporate mail from your system spool file into your folders.

       scan   Display a listing of a mail folder.

       show   Display a mail message.

       next   Display the next mail message.  (Exmh doesn't actually run this.)

       prev   Display the previous mail message.  (Exmh doesn't actually run this.)

       rmm    Delete a mail message.

       refile Move a message into another mail folder.

       repl   Reply to a mail message

       forw   Forward one or more mail messages.

       comp   Compose a new mail message.

       MH  keeps  track of the current folder and the current message in between uses of these MH
       programs.  For example: % scan +inbox  unseen  1713   04/14  foote.PARC@xerox.   Have  you
       started  blasting  cdroms  yet?<<Probably.   1715   04/14  FlashBack Publish  1232: Tactix
       Introduces Break through in Unix Ad 1716  04/14 FlashBack Publish  1234: CERT  Advisory  -
       NCSA  HTTP  Daemon  for  UNIX<  1717  M04/15  To:welch            PGP test<<-----BEGIN PGP
       MESSAGE----- Version: 2 1718 M04/17  flash@flashback.c   mime-flashback-w  MIME  FlashBack
       April 13th, 1995 1719 -04/16 Bill Wohler        Notes for MH Chapters 20-22<<Brent, I have
       been 1720+-04/17 "Allen R. Carl"    Re: Tabs<<Brent, where is this  -tabs  resource  se  %
       show  1717  (Message  1717  displayed) % next (Message 1718 displayed) % rmm (Message 1718
       deleted) % repl 1717 (Set up template for reply to message 1717, invoke editor)

       Each user has a .mh_profile file that stores general MH settings as  well  as  per-command
       settings.  Each line has a key, and a value.  For example, your mail directory is set with
       the Path profile entry: Path: Mail

       If your old mail system uses that directory already, just edit your .mh_profile to  change
       the name used for your MH mail folders.

MORE ABOUT EXMH

       This man page should get you started with exmh.  If you decide you want to know more about
       it, here are some of the features described in the other exmh man pages.

       MIME support.  Exmh can display MIME (Multipurpose  Internet  Mail  Extensions)  messages,
       either  directly  or  with the help of the metamail package.  The built-in editor lets you
       compose enriched text messages and insert files as parts of a multipart message.

       Mail Folders.  You can create other mail folders to hold messages about certain topics  or
       from  certain people.  You can create a hierarchical arrangement of folders, just like the
       hierarchical directory structure of the file system.  The folder  display  supports  these
       nested folders, and it allows you to nest folders to any depth.

       Mail  Filtering.  Mail filtering lets you sort mail into different folders before you read
       it.  If you get lots of mail, this is a great way to avoid plowing through junk mail  just
       to  get  your  important  messages.   The  folder labels are highlighted to indicate which
       folders have unread mail in them.

       Facesaver bitmap display.  If you have a facesaver database on your system, exmh  displays
       the bitmap face of the person that sent the current message (or their organization).

       Background  processing.   You can set exmh to run inc periodically, check for new messages
       arriving asynchronously in folders, run the MH msgchk program, or count up the messages in
       your mail spool file.

       Editor  interface.  You can hook exmh to your favorite editor using the exmh-async script.
       Or, Tcl-based editors such as mxedit can interact with exmh directly.

       Keybinding User Interface.  You can define new key bindings for Tcl commands that are part
       of the implementation.

       Aliases  User  Interface.   A  browser for your MH aliases lets you define new aliases and
       insert aliases into mail messages.

       Pretty Good Privacy (PGP).  If you have PGP, you can use it from exmh to  digitally  sign,
       encrypt, and decrypt messages.

       User Programming.  If the preference settings are not enough for you, you can program exmh
       more directly.  You can define new  buttons  and  menus  and  add  new  Tcl  code  to  its
       implementation.

SEE ALSO

       exmh-use, exmh-ref, exmh-custom, mh

AUTHOR

       Brent Welch, <welch@acm.org>

THANKS

       To  Xerox  PARC/CSL,  for supporting this work initially, to Sun Microsystems Laboratories
       for continuing the support, and to all the exmh users that contributed ideas and code.