I did not ask for it and I don't want it. This may just make me move totally from Yahoo.
I did not ask for the new mail and themes and I don't want it. this may just make me move totally from Yahoo. Who authorized this change? NOT ME!
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This help page explains how to switch back:
https://help.yahoo.com/kb/switch-back-previous-version-yahoo-mail-sln15936.html?redirect=true
Thank you!
Mail Support