Only option is new email address, it’s the same with the bas???ds that
somehow get your phone number, it’s all crockery, a real pain,
and just something we have to deal with.
Best bet is to set mail client to only accept mail from Contacts you
add to your email client, and keep a separate mail account for the
times you sign up for so called discounts etc, and another for what you
simply do not trust, like quora and the likes that insist you sign up
to get access to documents of interest.
The biggest culprit is anything android or google, just look at the access an app
asks for to run on your phone, and how google knows every single app you use
and when you open it, and how google takes your keyboard usage for analysis
to help provide a better user experience. There is no way to communicate in private
unless you first get rid of the usual suspects, of which there are many.