- Open Outlook.
- Click the File tab > Account settings.
- Highlight your current POP3 account and click Change.
- Note: The window that opens will tell you what type of email account you have. (Look under Type.)
- Choose More settings and click on Advanced.
- You should see a check box titled “Leave a copy of messages on the server”.
You can check the box "Leave a copy of message on server" in Outlook account setting.