I did a software update & now I can't open Mail I get the following message when I try to open mail

'You can't use this version of Mail with this version of Mac OS x
You have Mail version 4.5 (1084/1085). It can't be used on Mac OS X version 10.6.8 )build 10k549)'

I have read the help info 

I have made sure Mail.app is in the application folder

Thanks for any help with this
Since you state Mail.app is already in the Applications folder, follow these additional steps:


Download Safari 5.1.7 for Snow Leopard
Reinstall the Mac OS X Update v10.6.8 Combo v1.1
Reinstall Safari 5.1.7 for Snow Leopard
Reinstall Security Update 2012-004