Try This:
Step 1
Sign in to your Yahoo Mail account, and then back up all important emails you've received within the last seven days. You can forward the emails to another account, print important emails or copy the contents of the emails into text documents.
Step 2
Navigate to the Yahoo Mail/Messenger Restore Help Form page (link in Resources), and then sign in to your Yahoo account, if prompted.
Step 3
Select "Mail - Accidentally deleted messages on web Mail" or "Mail - Messages disappeared, unknown reason" from the "Describe the problem" drop-down list, depending on what is applicable to your situation.
Step 4
Select the time period in which the emails were deleted or have disappeared from the "Hours or Days" drop-down list.
Step 5
Enter your name, Yahoo ID and Yahoo email address in the requested fields.
Thanks,
Mrunited12
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