Check all mailbox folders, especially folder "Trash”.  Messages can be accidentally deleted from folders as well as from the "Trash". If messages are deleted from 'Trash'', then in this case, try to restore the deleted letters from Trash of the last seven days.

! Perhaps all new messages was collected by POP3 / IMAP protocol assistance. If you use MsOutlook, theBat or other programms in your mobile phone or other device - these programs by default, collect all your messages and don’t leave a copy on your Inbox server.

Check the POP3 / IMAP program settings. If you want to keep copies of the messages in your inbox, than go to Settings and choose the parameter “Leave a copy of messages on server”

! We do not exclude the possibility, that someone has obtained your user profile password and deleted all messages. We recommend you to change your password, secret questionand answer to it.