You can sign-up here for direct email announcement without joining anything, or providing anything except your email and name (just your first name if you wish to remain anonymous).
Subject of list:
Right now there is one list for new books (infrequent), blog posts (about 1 a week on average, sometimes 2) and book offers (e.g. 99 cent days, or signed copy for review offers).
If you have “followed” me on Amazon, be aware it only provides a notice when a new book is published. It does not provide notice of 99 cent days, advance copies, book signings, etc. These are even more rare than new books, and the list is the only notice of them.
Security of list:
The email list is managed by Send In Blue, and there is an unsubscribe link in every email. You will be asked to confirm your email address in order to prevent fake sign-ups, and to keep the list from accumulating invalid email addresses.
Using a list service also means that your email address is never sent to anyone else, like it would be on the “cc” if I used ordinary email. So you will not accumulate any unrelated spam from this sign up.