Junk files cannot be deleted

I recently updated skype and it was connected with my mail id. But after that my all emails were stored as junk files and because of that, the speed of my computer became slower than previous. So I wanted to install a system mechanic to clear the junk files. So can anyone tell me how to download system mechanic?

This doesn’t really make much sense. A skype update does not in an way impact your emails (cloud or local). I think you have other issues going.

If you want to try cleaning junk files (this might not help you), try bleachbit or CCleaner portable (not the full version) if you want a better UX.