mu4e v0.9.9 is out!

I few months ago, I introduced mu4e, a modest little emacs mail client that I wrote. It seems many people picked it up, great!

what's new?

I have just released mu/mu4e version 0.9.9. There are quite a few changes, both user-visible and 'under-the-hood'. I've also spent some time on improving the manual (pdf), and I'm quite happy about it.

Some of the more visible new things in mu4e are:

• Support for crypto (decrypting messages, signing them)
• Support for refiling (like mutt, Wanderlust)
• Dynamic folders (instead of hard-coding the sent/draft/trash/refile folder, they can be functions that return different folders based on the message we're dealing with, see the example below)
• Same for the folder to save attachments
• A lot of smaller and bigger UI improvements

Also, the core mu program has seen a lot of improvements (many of which directly improve mu4e as well)

• Better support for non-ascii locales / character sets, such as ISO-2022-JP
• Improved on-line help ('mu help ...')
• Performance improvements for threaded display (~ 25% for 23K messages)

For a more complete list, see NEWS.

dynamic folders

As mentioned, mu4e now supports dynamic folders. Before, you'd set your trash folder to some static string:

(setq mu4e-trash-folder "/trash")

In some cases, you may want to have a bit more flexibility – for example, have a separate trash-folder (or sent-folder, drafts-folder, refile-folder) for private mail and work mail. You can now do something like:

(setq mu4e-trash-folder
  (lambda (msg)
    (if (and msg ;; msg may be nil
          (mu4e-message-contact-field-matches msg :to "me@work.com"))
      "/trash-work"
      "/trash")))

refiling

After I have dealt with some e-mail, I either delete it or move it to some archive folder – refiling. For this, there is now the r keybinding, and mu4e-refile-folder; and a place where dynamic folders really shine:

(setq mu4e-refile-folder
  (lambda (msg)
    (cond
      ;; messages to the mu mailing list go to the /mu folder
      ((mu4e-message-contact-field-matches msg :to
         "mu-discuss@googlegroups.com")
        "/mu")
      ;; messages sent directly to me go to /archive
      ;; also `mu4e-user-mail-address-regexp' can be used
      ((mu4e-message-contact-field-matches msg :to "me@example.com")
        "/private")
      ;; messages with football or soccer in the subject go to /football
      ((string-match "football\\|soccer" (or (mu4e-message-field msg :subject) ""))
        "/football")
      ;; everything else goes to /archive
      ;; important to have a catch-all at the end!
      (t "/archive"))))

How cool is that? After reading my inbox folder, I select all messages (C-x h), press r, and they're all moved to the right refiling folder.

crypto support

mu4e already supported signing/encrypting messages, but now it supports decryption and verifying signatures as well. This was one of the most requested new features. I think it is still a bit rough, but it has been working very well for me.

so…

I think version 0.9.9 is a great new step for mu4e. It already goes far beyond I ever planned to do. I received a lot of suggestions for new features, which is great! I'm not planning to implement all of those, but I will try to make mu4e even more programmable – it should be easy to augment mu4e with your own little elisp-snippets – the Barbapapa principle of software, already so clearly present in emacs itself.

introducing mu4e, an e-mail client for emacs

background

I've haven't written too much here lately. This is because I have spent most of my emacs hacking time on mu4e, an emacs e-mail client. It's only slightly over six months old since its first release, but it has progressed rather quickly! So, I think it is time to give it an introduction to a wider audience. In future posts, I'll go into more detail.

E-mail is a very important means of communication for me; and for purposes of integration, it prefer to do my e-mail with emacs. For a long time, I used mutt with emacs as the editor; a few years back I switched to Wanderlust, and wrote a few articles about it.

There's a lot to like about Wanderlust: it's very featureful, and allows for a lot of customization. Still, there were a few things I was not fully happy with; the most important one was the speed of some operations; another annoyance was the fact that I got rather frequent cache-corruptions when using newer emacs versions.

So, what was I to do? Well, a few years back, I had written an e-mail indexer/searcher, called mu. It takes the messages in a maildir-folder, and allows you to query them. I wondered if I could use mu as the backend for an emacs-based e-mail client. So, I fired up emacs, started writing some code and some later I had a first version of… mu4e.

how does it work?

mu4e is an emacs front-end for mu; when you start it, mu4e connects to a mu server process (started on-demand). It accepts simple commands, and responds with emacs s-expressions, in asynchronous fashion. In practice, all the heavy work is done in this server process, and emacs shows the results when it is ready (usually almost instantly). Emacs does not need to wait for the backend, and things stay snappy, even with tens of thousands (or more) e-mail messages. The only operation that may still require some waiting is sending mail, since that uses the emacs built-in smtpmail, which blocks during its operation.

mu expects your e-mail messages to be stored in a maildir (a one-file-per-message system); you can get these mails there through tools like offlineimap or fetchmail. mu periodically indexes the messages, and stores the results in a Xapian database. A lot of what mu4e does is querying this database – so for example, what you see as 'my inbox folder' in the mu4e-frontend, is in fact just the result of a query of all message that happen to live in that folder. You can query for many things – message sender, subject, date, words in the body and more.

mu4e does not just query messages; it can also move messages between folders, delete them, modify their flags and so on (and afterwards update the database). All 'state' is in the file system, and the database is just a quick way to get to it; if you delete the database and then re-index, nothing is lost, and changes made with other tools (e.g. mutt) are picked up by mu as well.

trying mu4e

Some Linux distributions ship mu4e, but not necessarily a very recent version; and because mu4e is developing quickly, you may want to use the latest official release, or (if you are more adventurous) check out the git repository. You'll need GNU/Emacs 23 or 24, GLib, GMime >= 2.4 and Xapian.

After installing mu4e, you can check the mu4e manual, which should be fairly complete. In fact, one of the goals of mu4e is to make it easy to set up; for that reason, the documentation includes complete examples of how to set things up. The Getting started chapter should get you up to speed quickly.

So, give it a try if you're interested; the mu=/=mu4e project is very open to suggestions (and even bugs reports!), so feel free to put them here or subscribe to the mu mailing list.

a small tour

I'll end this with a number of screenshots, to give you a rough idea of how things look.

The main screen

When you start mu4e (M-x mu4e), you're taken to the main screen, which list the things you can do. The entries should speak for themselves. Note that you can define you're own bookmarks. In general, mu4e tries to make things as easy as possible, and provide auto-completions where possible.

The headers / view split-screen

The results of your queries are shown as a list of headers; if you click one of the headers, mu4e splits the screen horizontally (optionally, you can split the screen vertically, or only show the message view). You can customize the headers shown, re-order them and so on.

The message view supports html message, inline images, and has a mechanism to associate user-functions with messages and attachments (such as 'view in browser' or 'pipe through command'); see the manual for some examples.

The message composition view

Obviously, you can reply to messages, forward them, or compose a new message. For writing and sending messages, mu4e reuses emacs' built-in message-mode. There's support for auto-completing addresses (based on the e-mails you've sent/received before).

There's even (experimental) support for writing you're messages using org-mode, and then sending them as rich-text (html) messages.

parting thoughts

So, this was a short introduction to mu4e, barely scratching the surface, but hopefully conveying the main ideas. The manual discusses things in much more detail, and I'll write more about it in the future.

mu4e is still a young project, but, for what's it worth, I've been using it full-time for over six months, and a growing number of people are doing the same. So, if you're interested, give it try and let us know you think!

Have fun!

sauron: keeping an eye on what's going on

I'm a fairly busy person, and need to keep track of a lot of things. That includes following a bunch of internal IRC channels, attending meetings, meeting deadlines and so on. But I don't want to stare at my org-mode calendar, or flip through ERC buffers all the time.

Instead, I'd like to have one little emacs frame (window) that gathers these ('events'), and transfers me to wherever the event came from when I click it - some IRC-channel in ERC, my org-calendar etc. and other inputs. Note, using Bitlbee, you can include Facebook-contacts, GoogleTalk-buddies and Twitter-tweets, … in ERC - so, you can track just about anything.

In addition, with so many inputs, I'd also like the possibility to filter out unwanted events, and generate various light/sound effects and fireworks, proportional to the priority of the event.

For all this, I wrote a little emacs-tool called Sauron that does just that. M-x sauron-start pops up a frame that receives events, and M-x sauron-stop hides it and stops listening. It works with ERC, org, and listens for D-Bus messages; so it's pretty easy to get events from all over the place.

It's a bit of a balancing act to get all the important information while not being swamped in noise, but Sauron allows you to fine-tune it to whatever works the best for you. I've tried to have sane defaults though, so things should mostly work without too much configuration - but if you need the power, it's there. I also added some convenience functions to make it easy to get sounds and other special effects.

So - it's brand new, it is of seems-to-work-for-me-quality, and I'd like to invite others to try it out, hack it, give feedback, add new back-ends and so on – what better Christmas present to ask for!

There's documentation, examples etc. to be found in Sauron's github repository.

package management revisited

Ages ago we discussed ELPA, the emacs packaging system. It allows you to
browse through an online repository of emacs packages and install, uninstall
and upgrade them, all from within the emacs comfort zone (menu:
Options/Manage Emacs Packages).

Emacs 24.1 (a pretest is available) will include a version of ELPA --
package.el; the version included with emacs 24 supports multiple
archives. The official archive is the one provided by GNU, then there is
the current one for ELPA, but there's now a third one available: Marmalade.

Marmelade ('Spreadable Elisp') offers a very easy way for developers to
make their packages available to emacs users, and an even easier way for
users to test out interesting packages.

To use all available package repositories (GNU, ELPA and Marmalade), add
the following snippet to your .emacs:

(setq package-archives '(("ELPA" . "http://tromey.com/elpa/") 
                          ("gnu" . "http://elpa.gnu.org/packages/")
                          ("marmalade" . "http://marmalade-repo.org/packages/")))

This works out-of-the-box for Emacs 24; for Emacs 23, you'll need the newer
package.el, which you can get from the emacs 24 repo (if necessary, remove
the old package.el first).

Currently, there are 870 packages listed in the three repositories – a lot of
toys to play with! In fact, it is already getting quite hard to find what
you're looking for; a bit more structured way (maybe using categories) would
be useful. Also, a bit more information than the one-line description would
be very useful.

Nevertheless, it's a great addition to emacs, which will make it much easier
to play with packages – without even having to read the installation
instructions.

porting the zenburn theme to emacs 24

Just a small note: I already mentioned the zenburn color theme a couple of times. I have now ported the full (big) set of customizations to the emacs-24 format – find it at github; so if you run emacs 24 (the development version) and enjoy zenburn like me, you can give it try. Suggestions, additions are welcome.

Note, there seems to be a limitation with the :inherit-attribute for themes – in practice it means that some aspects of the theme may not work if a package sets the face before the theme does. Therefore, best to load the theme early from your .emacs or init.el; or alternatively visit the theme file (zenburn-theme.el in this case) and evaluate the buffer.

color theming with emacs 24

The emacs development team is hard at work on emacs 24. As far as I know, there is no planned date for it yet. I'll write more about all the new cool things when we're a bit closer to the release date, but I'd like to highlight emacs 24 color-theming already, as it's an area people outside the core development theme should be able to contribute to as well.

Here at Emacs-fu, we already discussed color-theming and in particular the zenburn color theme; this was all based on the color-theme-package. While being popular, there were a few problems with that package, which is why emacs-24 comes with a new scheme for doing this.

The current development versions of emacs ship with a few themes (tango, tango-dark and wheatgrass), which you can activate with M-x load-theme. It would be great to include some more color themes, and to encourage this, emacs maintainer Chong Yidong has written the GNU Emacs Theme Generator (currently in bèta), which helps you in the process of making a simple theme. This tool currently only support changing colors, and not e.g. the boldness or slant, but it's a nice way to get started, and to immediately see the results.

For more complex theming, there is M-x customize-create-theme; however, that is built on the (in my opinion) cumbersome customize-interface, so I'll probably start by creating a basic theme with the web tool, and then edit it by hand. If you design some attractive color theme and would like to propose it for inclusion in emacs 24, you can send it to emacs-devel.