Serv-U Version

Your question as written, doesn't make much sense. You can download/install the current version and run for limited time before you buy. There was in the main site Downloads where you might find prior releases, however I've not visited lately so not sure if there is a release from 2017, And consider there may have been more than one in the year 2017, so likely you will have challenge simply finding a release in 2017, and applying the license, And consider the security patches that have been released in these past 7 years...

Perhaps if you explain your objective someone can add better guidance