The related documents that you sent as a reference in recovering my emails is not applicable considering that I have not deleted all my mail
Your reference materials for mail recovery is not applicable to my situation. I have not deleted all my mails. It was lost when you change the version of yahoo. Please recover all my mails.
I recommend that you switch my account to the previous version of yahoo.
If an account is unused or dormant for 12 months, it is deactivated and its emails are deleted, more info here: help.yahoo.com/kb/SLN2018.html
If this does not apply to you, You can try doing a search or doing an email restore if the email was deleted in the past 7 days.
In case you are using a mail client such as Outlook or the Native mobile app, emails may be deleted by that third party client. We do recommend accessing your mail via yahoo.com or the Yahoo Mail app to avoid this issue.