Exporting your subscriber list isn't perfect. I did it after moving to https://tuhat.net, and then after posting from tuhat, got emails from subscribers asking who I was and why I was writing to them. The majority of said subscribers, came from an article I wrote about leaving substack, so you'd think they'd have figured it out.

Some of them were far less polite, never mind that it would have taken them less time to click unsubscribe then writing some insulting email to someone they chose to follow.