அனைத்துத் தயாரிப்புகள் ஆதரவு மன்றம்

Hi; I noticed today that many years of archived emails have disappeared in all but 1 account(yahoo). The only years still there are 2020 and 2021 in 5 different accounts. 5 yrs in 1 account and complete 24 yrs in yahoo account. These accounts archives that disappeared are not stored on the mail server but locally. What has happened??? Can I get them back? How do I stop this from happening?