Use Yahoo customer service, if unable to unblock Yahoo emails.

Yahoo comes with various features that make your work more reliable and also reduce the work time. Emailing platform is very essential for communication and it also allows you to send a single mail to multiple users at a time. It gives you option to block someone on its platform, but if you want to communicate with that person then you can unblock them. If you are not able to unblock someone on email, then you should check your internet connection and also try to reload the webpage. If you still face the same, then use Yahoo customer service. https://www.getcustomerservice.org/yahoo-customer-service/