Sent mails in inbox

One of our user has that problem. Since few days in his inbox folder began appear sent mails. Could any one give me any suggestion how can i get rid of that?

Subject: send and file

It sounds like your user is hitting “send and file” then Enter, when sending a message. “Send and File” brings up a dialog for you to choose a folder. The default is the top folder - which is the Inbox.

Your user should be instructed to simply use the “Send” button. A message which is saved when sent will automatically show in the Sent folder.

They may also want to adjust their choices in File>Preferences>user Preferences, Mail>Sending and Receiving. They can choose to automatically save all sent messages, not save any sent messages, or be prompted each time.