Installing Safari 4 Beta breaks Mail if you have the GrowlMail plug-in installed
by Jon on Feb.26, 2009, under Apple/OS X, Computers
As above …
To fix, simply remove the plug-in. Depending on how you installed it, the plug-in will either be in /Library/Mail/GrowlMail.mailbundle or in ~/Library/Mail/GrowlMail.mailbundle.
Open terminal and delete the folder above (depending on your installation) and all will be fixed. Re-install the plug-in when Apple have fixed the conflict, and remind yourself that it’s not called “beta” software for no reason!