You answer:

There could be many reasons for Yahoo Mail Down such as when you have internet connection, when Yahoo’s server is unreachable and down. You can click on the link here to get the Yahoo customer support team. When there is technical work going on the Yahoo site then, users face difficulty in accessing their Yahoo mail account. A team of professionals at Yahoo leaves no stone unturned in resolving their users’ issues.

https://www.numbersforsupport.net/blog/yahoo-mail-down/