SpamAssassin Milter on MacOS X describes how one person managed to get Spam Assassin up and running, server side, on OS X.

I managed to muddle through the foundational work, but was unable to get the sendmail distribution to unzip. The distro requires PGP key verification, which I was ignoring because I did not want to spend more time chasing half-documented implementations of SW for OS X all over the web.

So the bogus untarring could be because of that.

I am reminded that I am not a person who enjoys this sort of thing. I am reminded that I saw a copy of “Close to the Machine” in a used booksale the other day and thought, hm, I should read that some day. That which is broken shall remain so.