It looks like people have unsubscribed from one of your Mailchimp newsletters, and you would like them to subscribe again.
In Mailchimp, once someone unsubscribes from an email newsletter, you can’t resubscribe them again. If they did this accidently or they are ready to rejoin, they will need to submit their information in a MC signup form. This will update their email status to subscribed.
If you don’t already have a signup form connected to Mailchimp, you can create one by following these steps.
After signing in to MC → Click on Audience → Choose Signup forms
Scroll down and click on the Form Builder image or Manage Forms. In either case, the form builder will open. Here is Mailchimp’s helpdesk article on this topic: https://mailchimp.com/help/how-the-form-builder-works/
Once you are done, you embed or send the user the link where they can fill in their information again.
TIPS FOR SUCCESS
We liked the Form Builder because it gives you a hosted URL, so you don’t have to embed the form on your website. You can just send your people the link.
To encourage people to opt back in, make your form as short and sweet as possible. At the minimum, you need their email. We recommend first and last names, too. Obviously, you can have a longer formbigger opt-in, collecting more info, if you wish.
If you DO choose a longer opt-in form, we suggest making the additional fields optional instead of required. If your form is too long, people may decide not to opt in.