I have found that if I create a newsletter, then members that existed before don't get automatically added to the newsletter subscription even if I have enabled "Auto-Subscribe users to list" in the Newsletter plugin. The newsletter is in the same category as other protected content that all the members have, both old and new members. Only new members created after the newsletter get automatically signed up. How can old members be added to a new newsletter subscription? (except adding each member individually, which would be cumbersome if you have hundreds of members) Thanks!
You can rebuild newsletter database to achieve it aMember CP -> Utilities -> Rebuild DB -> Rebuild Newsletter Db Best Regards.