Anyone who installed Apple’s latest security release – OSX 10.6.5 – and uses Growlmail and/or Letterbox, will have been greeted by the “Mail 4.4 has eaten your plugins message”, again. A tiresome thing that happens everytime Apple updates Mail – they change the UUIDs and everything starts breaking.
There are two ways to fix and either works 1) The links above reveal an updated version of each or 2) you can upgrade manually by following these instructions. To fix Letterbox in the same way, simply run the defaults write… replacing GrowlMail with Letterbox.
Job done.