Contents Contents Custom Headers, incl. X-Faces


What's Mnenhy?

The primary goal of the Mnenhy project is to make some enhancements to SeaMonkey/Mozilla MailNews, since there're still plenty of comfort functions missing when compared to Netscape 4.x and other mail and news clients. Meanwhile, the Mozilla Foundation has released a stand-alone mail and news client named Thunderbird that is built upon the same core (despite some modification in the UI), so most of Mnenhy's features, especially the Custom Headers and the Folder Storage, are available there also.

But Mnenhy has more features that will enhance your browsing experience (various Text Codecs like ROT-13, Kenny, Unicode and more) with Mozilla and even Firefox or help you in developing for the Mozilla platform (Chrome Manager for manipulating the Mozilla chrome registry and Registry Viewer for viewing registry.dat type files).

By the way: The project name Mnenhy is an acronym based upon MailNews-Enhancements. The y has been added just for fun. :-)
And, lo!, it's pronounced like mn+any...

Download & Installation

The current Mnenhy version is always available for download and installation from The package contains all Mnenhy modules and several locales like English, German and Italian.

More translations are welcome! If you want to translate Mnenhy into your locale, please contact me!

Advanced Installation

When installing Mnenhy (below v0.8) in SeaMonkey or Mozilla, Mnenhy's installer provides some advanced, though purely optional, configuration options not available in an Extension Manager installation. Just access the XPI from the browser URL bar by:


where scheme is something like http or file. arguments must be the string representation of an array of objects, with these possible members:

The following (rather long) line will install the base content package, plus the codecs subpackage, plus the locales de-DE and en-US. It will use de-DE for the installation dialogs (because that lang argument came last) and will not check if Mnenhy is already installed:

   file:///mnenhy.xpi?[{lang: "pl-PL", locale: "de-DE", content: "codecs"}, {lang: "de-DE", locale: "en-US", overwrite: true}]

Preferences & Files

Mnenhy main preferences panel
Mnenhy main preferences panel

Mnenhy provides its own set of preferences panels that are available from the main level of the standard Mozilla preferences dialog or from the Thunderbird/Firefox Extension Manager. While the main panel allows to activate each Mnenhy module individually, some modules bring along their own subpanels.

Generally, Mnenhy stores its configuration in the Mozilla preferences system, in its own preferences hierarchy named extensions.mnenhy.*. But since some of the modules may produce large amounts of data, other files are created in the user's profile directory and, depending upon user interaction, possibly somewhere below the subdirectories chrome or extensions.

Mnenhy's package files are stored in the usual locations, i.e. the user profile's or application's chrome directory or the Extension Manager's file repository.

All these files will have names starting with "mnenhy"; they can be deleted after uninstalling if you plan to abandon Mnenhy.


Mnenhy has its own uninstaller that can be accessed via its main preference panel. While using the Extension Manager is of course possible (in Thunderbird or Firefox), it is recommended to use the Mnenhy uninstaller, because it reverts the modifications Mnenhy has made.

Currently, uninstalling Mnenhy will not delete the customization files mnenhy.rdf and mnenhy-folderstore.rdf in your profile, so any new Mnenhy installation can pick up your old settings. If you don't intend to use future Mnenhy versions, you can safely delete both these files.

Tips & Tricks


Most of the Mnenhy modules support logging of debug information, either to a file, the console or the JavaScript console. Add the following line to your user.js:

user_pref("extensions.mnenhy.log", "$mode");

where $mode is one of these values:

$modelog target
fileThe file mnenhy.log in the user profile.
shellThe text console. Start your Mozilla application with -console if your system does not provide a text console by default.
consoleThe JavaScript console.
anything elseNo logging.

Activating logging for Mnenhy will also set these preferences to get even more debug output (event though that is not written to mnenhy.log):

user_pref("javascript.options.strict",        true);
user_pref("javascript.options.showInConsole", true);
user_pref("browser.dom.window.dump.enabled",  true);

Logging is turned off for Mnenhy modules by default, so you have to activate it for each module explicitly. See the respective module documentation for details.

You can activate logging of the uninstall process by adding the following line to your user.js:

user_pref("extensions.mnenhy.log.uninstall", true);


If you find a bug in Mnenhy or if you have suggestions for enhancements, please open a report in the Mozdev Bugzilla. Make sure that it hasn't already been filed!

You may also contact me.


An extensive overview over past Mnenhy development can be found here.


If you have questions, corrections or suggestions, either post them to the newsgroup public.mozdev.mnenhy (mozdev/maduser) or email me directly.

And if you like Mnenhy, please send me a postcard: :-)
Karsten Düsterloh — Hohe Egge Oberweg 6 — D-45549 Sprockhövel (Germany)