When you are unable to receive the emails because of the storage full error. it means, something is wrong with the mail data or other settings. to fix that error, I have decided to make a few changes into the account. 1. Clear the spam box. 2. Remove the messages from other archives as well. 3. Clear the drive and other types of data as well. After clearing such types of data, your gmail will start working fine. in case, if it not showing you the emails properly. you need to visit: how to fix Gmail storage full problem?