Maybe you can get your email software to direct the offending mail to the spam folder.
I recommend Mail.com - It’s free and I’ve used it for years when “signing up” for something that I suspect might spam me. And within the account you can create up to 10 more alias addresses that can simply be deleted if they become inundated such as you described (they go to the same inbox).
Then check mail on the web or use a phone app called BlueMail to pick them up for you.
When a phone number is required to sign up I use a number I got through a phone app called Burner. Costs less than $2 a month.
I use Gmail; how do I list an email address as spam?
interesting tools
They also have a Mail.com app in the App store.