Seems like mailing lists are getting popular. I wish I could have those in my RSS reader.

RSS readers that manage mailing lists:

Inoreader: https://www.inoreader.com/blog/2020/02/declutter-your-inbox-...

Newsblur: https://blog.newsblur.com/2016/07/01/newsletters-in-your-new... (open source and self-hostable)

Feedly: https://feedly.com/i/pro

Also, Kill the Newsletter (https://kill-the-newsletter.com/) converts newsletters to RSS feeds, and is open source/self-hostable.

I really should get around to self-hosting my RSS reader.