eM client Pro version is for lifetime activation?

There are two types of Pro Licenses. The regular Pro License is valid for a specific release set of eM Client. So if you purchase one now, it will be valid for all 7.x versions of eM Client. A Lifetime Upgrades option will allow you to use the same license for all future releases so all 7.x versions, and all 8.x, 9.x etc.