Periodically subscriptions need to be reconfirmed. Since I have just begun sending updates after a long break, the emails are not all being delivered because the subscribers have not been reconfirmed recently. Never fear that if you enter your email address that you will be double subscribed. I check the list for duplicate emails.
The number of updates is not overwhelming, 2-3 times a month, if that. It takes time to write newsletters. I won’t deluge you!