How to prevent a gmail account from sending emails to my gmail?

I want to block a gmail account that keeps bothering me and sending me emails. I have a gmail too. Here are options:

1. I can “block” this account, however, the sender can still send the email. It will end up in my spam folder. This option is NOT ACCEPTABLE.
2. I can upload 15 Gb to my google drive, and all senders will get an “Undeliverable” email message. This option is better, however, the sender will still be able to send an email.
3. Ideal option is: the sender clicks send, and there is a “circle” spinning and spinning, but the message is not being sent. The sender is prevented from sending an email in the first place. How to make this happen?