Install Sendmail was a script that I worked on several years ago that made it very easy to configure Sendmail. Unfortunately, the original download site is in somewhat of a bad state and it’s no longer possible to download Install Sendmail from there. Here’s a new download link:
This will probably be the last version of the script. Sendmail has moved on so it might not even work any more, and I recommend using Postfix which is much easier to use.