Substack for Blog Posts

Several of you have been using Substack. I’m looking at it for all the reasons Tom mentioned in his podcast about Substack. I’ve been writing blog posts for over a decade, on my website, with an email notice for each post and a short version going to subscribers via AWeber. My question is: If I move to Substack, does that replace any new posts on my website? Or do I post them in both places? If I do that, then subscribers will receive two copies/notices, which I imagine will irk them. In short, what are best practices for integrating Substack with an existing website of content? THANKS!