For this particular newsletter they get a welcome email with a link to an article explaining atomic newsletters in depth.

Then they join at the most current issue.

For another newsletter I’m working on, I’m loading up an evergreen sequence that will start subscribers at the beginning.

It’s up to you how you want to do it.

With ConvertKit and Beehiiv your newsletters get archived, so new subscribers can always go back and sift through your old editions.