Unblocking someone on Gmail is simple. On a PC, go to Gmail’s Filter and Blocked Addresses settings to see a list of blocked emails, where you can unblock one or more addresses. In the Gmail app, ...
Gmail removes an email address or domain from your list of blocked addresses through the Filters and Blocked Addresses page in the settings. The first step is to locate the filter that deletes emails.
To block and report emails in Gmail on desktop or mobile, click or tap the "More icon" or the "Report spam" button.