eM client deleted my all the Inbox messages on Gmail server

em client received all the messages from my gmail account but not left any message there, removed or delete that all from inbox, it not leave one copy on server. How can I get back my deleted messages? and how to set em client to not to delete messages from server?

Hi, are you using POP or IMAP for receiving emails?
What version of eM client are you using?

Thank you,