POP3: Download all your emails to your favorite device keeping your online email empty to receive more emails. For best practice, forward all your email to your public or personal emails like gmail, hotmail, yahoo mail for convenience. Below is a step-by-step (screen shot by screen shot) on how to setup your Microsoft Outlook to receive a POP3 email account. You can use the same settings on any device. It might look different by the answers are the same.
IMAP: Access your email from multiple devices while downloading a copy on each device. Your email stays on the cloud so all your devices stays current. CAUTION: Eventually, any email inbox will get full so make sure to login to webmail from time to time and delete spam or old unwanted emails. Remember, you have copies of these email on all your devices so feel free to make plenty of room.