Gmail provide a visible list of blocked emails. But you can view your blocked addresses via Google Contacts:
So, to “check blocked emails,” you actually check your for messages from senders you blocked. how to check blocked email on gmail
Review your blocked sender list. Important: If you can't find the sender's message, you can unblock them from your Gmail settings. Google Help How to Check Blocked Emails on Gmail (Step-by-Step Guide) Gmail provide a visible list of blocked emails