Hmghsshatsignrediffmail.com — automatically deleted the mail from inbox

Sir,
We are using rediffmail since 03 years. Now we have face a problem. Our previous mails has been automatically deleted from the inbox. The new arrival mails are also moved to deleted /trash folders. The previous in mail before 06 mar 2018 has been automatically deleted. As we are govt. Organisation we are facing the problem. Pl look into the matter