How To Fix Letterbox Mail plugin for Mac OS X 10.6.5
Letterbox is a popular plugin for Mail.app that gives you a wide screen three-pane view in Mail, unfortunately the Mac OS X 10.6.5 update broke this plugin. If you don’t mind getting your hands a bit dirty in the Finder, you can fix the plugin to work in 10.6.5 by editing a file. We’ll walk you through it:
Fixing the Letterbox plugin for Mac OS X 10.6.5
1- From the Finder, hit Command+Shift+G and enter ~/Library/Mail/ then hit Go.
2- Open Bundles (Disabled) rather than Bundles .
note: if you have already opened Mail, the plugin is disabled, if you haven’t opened Mail yet, it will be in Bundles
3- Right-click on Letterbox.mailbundle and select “Show Package Contents”
4- Now open the “Contents” folder inside the Letterbox.mailbundle contents
5- Using a text editor, open Info.plist (you can use TextEdit, don’t use Word)
6- Scroll to the bottom of the Info.plist file and look for “SupportedPluginCompatibilityUUIDs” which is surrounded by key tags, below that will be a bunch of hex strings surrounded by string tags
7- Add the following two strings to the bottom of the list (inside the array tags):
The newly inserted strings should look as follows:
8- Save these changes to the Info.plist file
9- Go back to the Mac OS X desktop and hit Command+Shift+G again, then enter ~/Library/Mail/
10- You’ll see these two folders again: Bundles and Bundles (Disabled), what you need to do is move the Letterbox.mailbundle plugin from the (Disabled) folder to the Bundles folder. Do this just by dragging the file from one folder window to the other.
11- Relaunch Mail.app
Now when you open the Mail app again, your Letterbox plugin will be restored and everything should be working in full widescreen three paneled glory again.