how can i retrieve e-mails lost when yahoo change mail format?

[Teddy]

When Yahoo changed their mail format, several of our saved folders lost the e-mail in them. In other words they were empty and several years mail and photos were lost.

[Arthur Dent]

Messages are missing from the inbox or another folder - http://help.yahoo.com/kb/index?page=cont...=PROD_ACCT

After reading the tips about filtering and spam folders, if it still appears your email was unexpectedly lost, we have a limited window of 24 hours to retrieve your messages by reverting your mailbox to a point in time. Since this process will destroy any messages received after the point you select, we strongly recommend caution.

Restoring emails or IMs - http://help.yahoo.com/kb/index?y=PROD_MA...sions=true

Yahoo! Mail/Messenger Restore Help Form - http://help.yahoo.com/l/us/yahoo/mail/ym...store.html

Using the Attachments application - http://help.yahoo.com/kb/index?page=cont...OD_MAIL_ML

Overview of the Photos folder - http://help.yahoo.com/kb/index?page=cont...sions=true

Ways to contact Yahoo Customer Care
Call toll-free 1-800-318-0612 or 1-866-562-7219
Twitter - https://twitter.com/YahooCare
Facebook - https://www.facebook.com/YahooCustomerCare