The amount of telemarketing calls I receive is on the low side. Most of those unwanted calls I receive are the 703-next three digits the same as my mobile number. My email blocks using Sieve code, blocking it down to the email, subject, and even spam tag, and very few false positives, I have only received less than 25 spam emails in the last two years ago. I do allow Chick-fil-a to email me because I believe in their values. Others I either do not give them my email address. Or if online order, I unsubscribe once or twice on the first unwanted marketing emails, and if that does not work, my Sieve code I set up to block their email and it sends an automated reject email saying their email was not received and let them have fun hitting the delete button at their end which have done with the Washington Post, Figis, and others. If you are interested in Sieve email blocking,
https://www.fastmail.com/ has it, and the $20 a year I pay them for it since 2003 is well worth it.