Contrary to popular opinion, I don't think the technical aspects of operating a mail server are all that hard. Perhaps I'm underestimating the learning curve since I've been doing it for 27 years. (If you're running your own mail server, you are the sysadmin.)

The frustration comes with scenarios such as the one outlined in this blog post, where small mail server operators get bullied even though they are doing everything right. I can completely understand not wanting to operate a mail server due to this situation, or not having interest in leveling-up server administration skills.

For those of us who do have expertise in running mail servers, it's a shame we have to deal with these obstacles.