Part 3 nicely continues the first two parts of this series. IMO some of its readers may look for this section to be one for specific troubleshooting. I don't think that's useful, preferring instead to read more general comments if possible.
There must be dozens of excellent forums to trouble shoot problems. My impression is that they do not relate to anything in this series of articles. My current Sendmail, for example, is totally screwed by some Apple or third party installer. I knew that before reading Part III.
I suggest all of us learn to monitor our systems so that some late blooming problem is not attributed to something recent. It would also appear that some readers may have forgotten the content of Parts 1 and 2.
And yes I do have Sendmail working fine on another Mac and find not a thing wrong with this article or its instructions. The bulk of my "education" on use of Terminal is derived from this series, a PDF "for beginners" I snagged somewhere and reading the "man" files at lenth <sigh>...
With all due respect......
I remain a geek NOT but one who is interested. :)