4.1 Overview

An example headers view:

Date V       Flgs  From/To             List       Subject
06:32        Nu    To Edmund Dantès    GstDev       + Re: Gstreamer-V4L...
15:08        Nu    Abbé Busoni         GstDev         + Re: Gstreamer-V...
18:20        Nu    Pierre Morrel       GstDev           \ Re: Gstreamer...
2013-03-18   S     Jacopo              EmacsUsr   + emacs server on win...
2013-03-18   S     Mercédès            EmacsUsr     \ RE: emacs server ...
2013-03-18   S     Beachamp            EmacsUsr   + Re: Copying a whole...
22:07        Nu    Albert de Moncerf   EmacsUsr     \ Re: Copying a who...
2013-03-18   S     Gaspard Caderousse  GstDev     | Issue with GESSimpl...
2013-03-18   Ss    Baron Danglars      GuileUsr   | Guile-SDL 0.4.2 ava...
End of search results

Some notes to explain what you see in the example:

• The fields shown in the headers view can be influenced by customizing the variable mu4e-headers-fields; see mu4e-header-info for the list of built-in fields. Apart from the built-in fields, you can also create custom fields using mu4e-header-info-custom; see HV Custom headers for details.
• By default, the date is shown with the :human-date field, which shows the time for today’s messages, and the date for older messages. If you want to distinguish between ‘today’ and ‘older’, you can use the :date field instead.
• You can customize the date and time formats with the variable mu4e-headers-date-format and mu4e-headers-time-format, respectively. In the example, we use :human-date, which shows when the time when the message was sent today, and the date otherwise.
• By default, the subject is shown using the :subject field; however, it is also possible to use :thread-subject, which shows the subject of a thread only once, similar to the display of the mutt e-mail client.
• The header field used for sorting is indicated by “V” or “^”¹⁹, corresponding to the sort order (descending or ascending, respectively). You can influence this by a mouse click, or O. Not all fields allow sorting.
• Instead of showing the From: and To: fields separately, you can use From/To (:from-or-to in mu4e-headers-fields as a more compact way to convey the most important information: it shows From: except when the e-mail was sent by the user (i.e., you) — in that case it shows To: (prefixed by To²⁰, as in the example above). To determine whether a message was sent by you, mu4e uses the variable mu4e-user-mail-address-list, a list of your e-mail addresses.
• The ‘List’ field shows the mailing-list a message is sent to; mu4e tries to create a convenient shortcut for the mailing-list name; the variable mu4e-user-mailing-lists can be used to add your your own shortcuts. You can use mu4e-mailing-list-patterns to to specify generic shortcuts, e.g. to shorten list names which contain dots (mu4e defaults to shortening up to the first dot):

          (setq mu4e-mailing-list-patterns '(``\\([-_a-z0-9.]+\\)\.lists\.company\.com'')))
  

• The letters in the ‘Flags’ field correspond to the following: D=draft, F=flagged (i.e., ‘starred’), N=new, P=passed (i.e., forwarded), R=replied, S=seen, T=trashed, a=has-attachment, x=encrypted, s=signed, u=unread. The tooltip for this field also contains this information.
• The subject field also indicates the discussion threads ²¹.
• The headers view is automatically updated if any changes are found during the indexing process, and if there is no current user-interaction. If you do not want such automatic updates, set mu4e-headers-auto-update to nil.
• Just before executing a search, a hook-function mu4e-headers-search-hook is invoked, which receives the search expression as its parameter.
• Also, there is a hook-function mu4e-headers-found-hook available which is invoked just after mu4e has completed showing the messages in the headers-view.