So I've been using Thunderbird for about 16 months now, and I finally decided to fix an annoyance. Anytime I get an email from someone using Outlook (often), any smiley faces they use in their message come across as the letter "J". It happened so often I kind of got used to it, thought of a J as a weird smiley. But that's not the correct behavior when something bothers you, so I found an implemented a fix I found. You can find the same info elsewhere, of course - a million monkeys and all that.
Go to your Firefox (you are using Firefox, right?) directory and find the res/fonts folder (on my computer it was at C:\Program Files\Mozilla Firefox\res\fonts).
Use wordpad to open the file fontEncoding.properties.
After the line "# Symbol font" add this: encoding.wingdings.ttf = windows-1252 encoding.wingdings2.ttf = windows-1252 encoding.wingdings3.ttf = windows-1252 encoding.webdings.ttf = windows-1252
Now copy this file (or the entire directory) into your Thunderbird install directory under ...\res\fonts (for me, C:\Program Files\Mozilla Thunderbird\res\fonts). There wasn't a fonts directory there before, so I had to create it.
Then restart Thunderbird. Test by opening a file that had included a J, or just get someone running Outlook to send you a smiley. 
Update on 10/29/08
So it turns out the latest version of Firefox (the fantastic Firefox 3) does not include the fontEncoding.properties file. Bummer!
I looked at the file I have and the copyright/license seems to indicate it can be distributed for free. Working under that assumption, I've made it available here.
YMMV, don't take any wooden nickels, this might blow up your computer, use with care, etc.
Download fontEncoding.properties
Enjoy!
Thanks a lot, this had been bugging me for quite a while.
Posted by: Rob | April 18, 2008 at 05:42
Thanks, works great!
Posted by: Leo | May 28, 2008 at 05:13
Daniel, can you help me? I just changed to Thunderbird from Outlook (thanks god), and I can not get it work.
I don't have fontEncoding.properties in my FF folder at all. Only files like math*.properties.
I did create fontEncoding.properties in my thunderbird folder, as you advised, put the # Symbol, and the encoding settings, but I still get the Js.
(Vista/Thunderbird 2.0.0.17)
Please, please help. (I did not find any other solution worth to try.)
Posted by: Zolo | October 14, 2008 at 13:13
Indeed there is no such a file like fontEncoding.properties with new FF 3.0
Posted by: wabik | October 22, 2008 at 07:20
Sweet! Tested OK on Win XP with FF3 and TB2, although I had to get the file from somewhere else (did a full search and found it in, of all things, my Zend Studio for Eclipse installation directory). Copied it to the right Thunderbird-folder, and hey presto; smileys!
Posted by: Espen | October 29, 2008 at 08:37
Works great. Didn't have the file fontEncoding.properties, so just created it and only pasted in your lines, worked like a charm! Thanks a bunch! J :P
Posted by: Eran | November 18, 2008 at 05:51
Thanks a lot, this bugged me. You don't need Firefox's fontEncoding.properties, you can just use a blank file with:
# Symbol font
encoding.wingdings.ttf = windows-1252
encoding.wingdings2.ttf = windows-1252
encoding.wingdings3.ttf = windows-1252
encoding.webdings.ttf = windows-1252
That's all.
Posted by: Rob | January 13, 2009 at 05:48
I'm currently on FF 3.0.5 and cannot get Wingdings or Webdings to work - I tried the suggestions above adding the fontEncoding.properties to C:\Program Files\Mozilla Firefox\res\fonts foldery, but still nothing.
I need to get it to work so I can tell others how to view this page - http://www.purplehell.com/riddletools/wingdingschart.htm using FireFox on my site.
Please help.
Posted by: Jennie | January 25, 2009 at 02:12
Yay! It works-- made my own fonts folder and fontEncoding.properties file as Rob suggested in Thunderbird and all my Js are smileys!
Posted by: Jenn | July 28, 2009 at 16:14
Thanks for the info! I can now Not burst a blood vessel in my eye when I used to see the infamous "J" in an email.
Posted by: Jason | September 24, 2009 at 18:49
Excellent! Thanks for documenting this!
Posted by: Paul | November 09, 2009 at 21:32
This had been bugging me for quite some time now... But adding the properties file was a quick fix! Thanks!
Posted by: Henri | November 17, 2009 at 03:35
Hey! It worked great for me with Windows Vista + Thunderbird 2.0.0.23. Had to create the font folder and fontEncoding.properties file from scratch with Wordpad in administrative mode. Used the 5 lines posted by Rob up there for the file content. Restarted Thunderbird, et voilà.
Thanks
Posted by: Yann | December 08, 2009 at 05:01
I'm running Thunderbird 3 Portable and have carried out all the above but my old outlook signature which includes wingdings and webdings will not display, the 2 font images are a mobile phone and telephone, any help would be most grateful.
I just get the chars below:
(
È
Posted by: Ian | December 18, 2009 at 08:26
The workaround doesn't work either for Firefox 3.5.6 or Thunderbird 3.0 on XP.
Posted by: s.rey | December 28, 2009 at 19:17
Yup, not working in Thuderbird 3.04 (Win7)...
Posted by: Rob | April 06, 2010 at 18:23
Not working in Thunderbird 3.0.4 (Win 7 x64) either.
Posted by: Thomas | June 07, 2010 at 06:08
Not working in Thunderbird 3.0.5. Is there any other workaround for this?
Posted by: tb | June 22, 2010 at 17:19
Also not working for me in Thunderbird 3.1 on XP :(
Posted by: Darren | July 06, 2010 at 17:05