When you check your email with an IMAP connection, you are accessing and managing your email directly from the email server.
Access: Since the emails are stored on the email server, you can access and manage your email and email folders from multiple computers or mobile devices.
Storage: If you have limited online storage space, you may need to delete some emails periodically to avoid exceeding your storage capacity.
Backup: The server is backed up for disaster recovery only. You should implement an effective backup system for your computer, in case you need to retrieve lost or deleted emails.
Internet Connection: If you do not have an Internet connection, you cannot access your email.
When you check your email with a POP connection, new email messages are downloaded to your computer and are then deleted from the email server.
Access: Since your email is stored on your computer, you must be at your computer to access your email.
Storage: You don’t need to worry about running out of online storage space. Since you’re downloading your emails to your computer, you can keep as many emails as your computer can store.
Backup: You should implement an effective backup system for your computer, in case you need to retrieve lost or deleted emails.
Internet Connection: You will need an Internet connection to download email, but you can view your downloaded email offline (i.e., without an Internet connection).