Why switch from POP3 to IMAP?

With the POP3 protocol, downloaded e-mails are deleted from the server, which means they cannot be downloaded again (e.g. from a laptop or via webmail). Accessing e-mails via POP3 in Outlook includes the possibility of leaving copies of your messages on the server. However, the different server parameters often result in messaging interface problems. Furthermore, this system does not show when messages have been processed, read or replied to.