Here's a solution for all who want to use winmail and windows 8.
The procedure is almost the same as windows 7 , but we will need a dll file.
First , we do the same procedure as in windows 7 :
a) Take ownership of winmail forder ( if you use windows 8x64 , you need to take oweneship of program files/winmail and program files(x86)/winmail). Remember to check the " show system files " before that.
b) Delete all the files in winmail forder and replace them with the windows 7 / winmail files.
c) Copy msidcrl30.dll to c:/windows/system32 folder
d) Now , we have to register the above dll. Open cmd and type : regsvr32 "c:/windows/system32\msidcrl30.dll" and press enter.
Reboot , just in case , and you're done !!