For what it's worth I find it minorly annoying when people send me emails about my posts. I'm happy for people to comment on them, but typically an email is an invitation to have a private discussion and I'd much rather talk publicly (https://www.jefftk.com/p/comment-dont-message)

And on the flip side, there are people like Noam Chomsky who reply to all emails they receive:

https://www.reddit.com/r/chomsky/comments/6a23eg/how_long_do...

You may get more comments/emails than I do. I think I've gotten 3 worthwhile comments and 2 emails in the 8 years my blog has been active. I actually turned comments off, because I was getting thousands of spam daily, and that seems like a waste of everyone's time.

I host my comments externally. For example, https://www.jefftk.com/p/mosh is currently on the HN frontpage as https://news.ycombinator.com/item?id=22810589, and I think of that like my comment section. I have my blog pull in the comments from there: https://www.jefftk.com/p/mosh#hn-22811119

I also pull comments from LessWrong and Facebook, though the FB comment integration is pretty temperamental.

Is there a way to comment on your post if it's not been posted to Hacker News/Facebook/LessWrong?

I post everything to FB and LW. If you want to comment on HN and you think it's a post that's relevant here you could submit it?

I don't submit things to Hacker News :(

I think comments are probably easier to interact with, but they're more hassle to set up and maintain :( FWIW, I often take interesting points from emails I get and add them as "updates" to blog posts.