This design allows you to manage your email on the server. This can be beneficial if you have multiple devices for which you wish to access and manage your email. IMAP is designed primary to allow you to MANAGE / ACCESS your email.
Advantages
POP is primarily designed to allow you to connect to the server, check for mail, download any mail that is waiting and then disconnect. It is not designed to allow you to manage your email, but merely to collect it so you can perform all the management in your mail client *offline*.
Advantages
Conclusion
We recommend using POP3 and configure your email client to not leave a copy of messages on the server. Why? Because it is important for you to keep a copy of every email on your computer. This allows you the ability to search and check emails in the future. Especially if you receive orders via email.
If you have multiple devices (say a work computer and a mobile phone), then what we would suggest is that you configure the work computer to NOT leave a copy of messages on the server. Then on your mobile phone configure its mail client to leave messages on the server. That way if you are out of the office, then your work computer would be turned off, so now using your mobile phone you can receive all emails that are sent to you. When you return to your office and turn the work computer back on, it will check for mail and download a copy of every email that is on the server (even those you read on your mobile phone). This way it ensures you had the ability to view any emails while you were out (incase any were important), but still then ensure your primary computer has been able to download a copy of every email received to ensure you retain a copy.