Constant stream of sandboxd Mail error messages in Console

I'm having the exact same issue. Problem is that it sends Mail's CPU usage up to a 100% and causes my Mac to slow down.

What can we do about this?

Me to, same message on console! very frustrating

Same as me!! Please Apple tell us how to fix this

I don't have cpu at 100% and you?

Any plugin installed?

What do you get showing up if you use Disk Utility to repair permissions? Have you tried that yet?

Tried.. no success!

I dont have 100% CPU but the log is there.

I get this message for lots of things

26/07/2012 13:08:44.996 sandboxd[36062]: ([7294]) Mail(7294) deny file-read-data /Library/Preferences/com.apple.mail.plist

26/07/2012 13:10:00.000 kernel[0]: Sandbox: sandboxd(37278) deny mach-lookup com.apple.coresymbolicationd

26/07/2012 13:10:00.192 sandboxd[37278]: ([37276]) QuickLookSatelli(37276) deny file-write-create /Users/sean/Library/Caches/com.apple.quicklook.satellite

26/07/2012 13:10:00.806 sandboxd[37278]: ([37276]) QuickLookSatelli(37276) deny file-read-data /Library/Preferences/.GlobalPreferences.plist

26/07/2012 13:10:01.006 sandboxd[37278]: ([37276]) QuickLookSatelli(37276) deny file-write-create /Users/sean/Library/Caches/com.apple.quicklook.satellite

Same log form com.apple.mail.plist and com.apple.coresymbolicationd.

Your others log entries they refer to a cached file. You can try to clean your cache.

Which cache? hHw do you clear it?

I've renamed:

with .bak on the end and the message has dissapeared. Can't see any issues yet, if I do I'll just rename back...there wasn't much in the .plist file anyway.

For the cache you can try to use Onyx fo ML

http://www.titanium.free.fr/download.php?sid=9e8813e87a5bdf981f892f21f738ca34

Deleting that plist you probably reseted all mail settings!

Same problem here. I have a Mail rule that is supposed to run an Applescript, but Mail is not executing the Applescript. It is just spewing sandboxd errors.

I am getting exactly the same errors in the logs.

Seems like Apple's own Mail app does not behave correctly and is constantly being kicked by sandboxing daemon.

Not very nice since ...

I was seeing this too. In my case it was reporting the error every 2-3 seconds.

I notice that my "/Library/Preferences/com.apple.mail.plist" was quite old, and clearly came from a previous version of Mail (in my case, perhaps from Mac OS X 10.5 even...)

Is everyone seeing this done an upgrade installation of Mountain Lion?

I renamed the file and the errors stop immediately. I had a look in it, and it doesn't seem to have anything important for current Mail, so I've actually deleted the file. No more errors.