They cannot be viewed on other computers connecting to that E=mail account, including Webmail.

Messages sent, moved, or deleted from a computer using POP can only be viewed on that individual computer's folders. Any changes you make will NOT be seen by anyone else who accesses the email account (because you are only making changes to local copies). POP3 allows you to download copies of your email messages to your personal computer. This option is most recommended for users who connect to E=mail accounts from many computers. All messages and folders can be viewed from any computer connecting via IMAP, including Webmail.

Depending on program configuration, these messages may be temporarily saved on the computer for offline viewing. This is also perfect for when people wish to always have their messages, including sent messages and message folders, saved on the server. This can also be used for multiple users who need to access the same email account. This is the perfect solution for those with mobile devices, such as phones or tablets. Any changes you make (delete, reply, forward, move) are seen by anyone else who logs into webmail or IMAP. IMAP4 allows you to read emails as they appear on the hosting server. Search Bluehost Web Hosting Help Email POP vs IMAP IMAP (Internet Message Access Protocol)

Bluehost email settings pop3