[forgotthepasswd]

I had a Mailchimp list on a very specific niche, and a website with the sole purpose of offering the signup. Lots of people signed up. I used double opt-in, lost a few there. Then, every email I sent had the conspicuous unsub link right on the top. Few people unsubscribed. That list had some 20% open rate and 12% click rate IIRC. That was many years ago.

I noticed some correlation: the larger was the time since signup to receiving the first newsletter, the more people were likely to unsubscribe.

I'd say, send those newsletters, or your subscribers may forget about you.