It is possible to shift from the new version of Yahoo Mail to the old version. The full version is more modern and recommended by Yahoo. However, if you prefer an easier version of the email, you can use Yahoo Basic Email.
Yahoo mail full version includes personalized, filters, themes, stationery, online image attachment, etc. The Basic version does not cover these features.
We hope you understand every step about how to switch between the basic and full version of Yahoo mail, but if you are getting issues to understand any steps or you are still facing the issue then you can contact Yahoo mail customer support to solve your problem.