Since forums dedicated to open source tools seem to contain nothing but problem reports and complaints, I thought I would offer some kudos instead.
So I managed to get MIAB installed last night with no issues. The only complications were due to my domain
registrar’s (Namecheap) confusing interface for setting up glue records. It took an embarrassingly long time to figure that out. The wait for everything to percolate through DNS didn’t help, and at one point I was worried because a tool for checking on DNS reported everything as fine, but the MIAB status page disagreed. A bit of patience and everything began to work. At first, GMail was spamming everything it received from the new domain, but it began to work over-night.
Nothing that I can really complain about. Everything just seems to work.
After doing a bit of reading into the alternatives, I see no reason to try any of the competition. MIAB looks like the best of the bunch.
And an extra kudo for mentioning the XYZ top-level domain in the install documentation and video. No longer will I hesitate to buy a domain for demo purposes.