My yahoo mail suddenly do not work for both phone and web browser:
For these things to not happen to anyone, Yahoo team should be accountable and responsible as well. Since most of the clients if not all have other linked emails and mobile numbers to their yahoo account, you should send even simple updates also when updating versions to avoid errors. This is especially helpful when someone is in emergency and needs to retrieve emails or any important information from their account. Be considerate also when the client has a hard time dealing with verification processes, specially if the yahoo mail itself is the problem or has caused the trouble.
Have a good day.

Hi there,
Could you please message us on Twitter at @YahooCare or on Facebook at Yahoo Customer Care? We'd like to look more into the issue you're experiencing. In case you do not have a social media account, we are also available at: help.yahoo.com
Looking forward to your reply!
Thank you,
Yahoo team