You appear to be missing Resources, worth 68.1MB. Right click on Mail.app to see Package Contents. I'm betting Resources is AWOL. If you still have the 4.5 around, you could move Resources out from there into the new one. But doing that will change you to the owner, which won't be right. You must change it back in Get Info (CMD-I) for Resources, as per the screenshot below. Unlock the padlock to do that. Make sure to hit Apply to enclosed.
At least an old post I finaly found kind of helps thanx KevinKendal.
My mail v4.5 is gone also I dont have the disk to reload as all my stuff is not in this country and in storage. SO a lesson already,
apple cant be trusted just like any other large org.
after many months of knowing about the problem they still let users upload a 'security fix?' that stuffs your system up
now my probem is who can send me a copy or how do i get a copy of V4.5 so I cna start to fix this. I would move on to not using mail this way but have history and current mails i need to access. Once done will move off apple app onto gmail direct.
You can get Mail 4.5 from Optional Installs on the install DVD. Just open it while it's sitting on your Desktop. Don't boot from the DVD. Make certain it's in the correct place in your Applications folder and not inside some enclosing folder. Remove any other Mail. app. Then run the update again.
Uh oh, just read no disc. Can you bring a Flash drive (thumb drive) to an Apple Store or Apple Repair and let them put Mail 4.6 on it, maybe.