I only have like a dozen email addresses. Several of them are for junk mail and subscription type stuff. Do you... not have a junk email address? I would strongly encourage you to start on that, because, even just a stupid gmail account you never use for anything important but use for junk is probably a life changing situation for you if you've never heard of doing something like this.
Edit: Super power here is setting up a 1Password Identity (or whichever tool you use, hell, even a snippet) to auto fill junk email in when signing up for stuff vs not-junk email. I have three identities. One for work, one for personal, one for junk. Makes this stuff super easy and fast.
I wasn't trying to make a point about price (e-mails are practically free). The book could cost half a penny and my comment would still stand. People just view items that cost something differently than genuinely free items, and not in a rational, economic way.
Edit: Super power here is setting up a 1Password Identity (or whichever tool you use, hell, even a snippet) to auto fill junk email in when signing up for stuff vs not-junk email. I have three identities. One for work, one for personal, one for junk. Makes this stuff super easy and fast.