Not the kind that forwards links. The kind where you sit down every week and work something out in public, and people reply. You have done that a hundred times, or three hundred. Somewhere in that archive is the best thing you have ever written, and a reader who found you last month will never see it, because it is issue 41 and the archive page stops at the newest twenty.
Every newsletter writer knows which issues those are. The one that got forwarded for a year. The one people still quote back to you. The three that, read together, say the thing you have been circling for a decade. They are a book. They are just filed by date.