This is the most common method for managing your blocked list. You do not need to have an email from the blocked person to do this; you can access the settings directly.
The Gmail app for iOS and Android does not have a dedicated "Blocked List" settings menu like the desktop version. You must unblock the sender directly from an email. unblock sender gmail
If you are expecting an important email that was sent while the sender was blocked, you must manually retrieve it: This is the most common method for managing
If you have a recent email from the person you want to unblock (likely in your folder), this is the fastest method: this is the fastest method: