In general, these terms denote how your email program (Macmail, Outlook, Thunderbird, etc.) handles your email message delivery and where those messages are stored. There is no correct answer to this question and largely the answer depends on user preference.
If you check your email on only one device, POP is likely the protocol you want to use. Although most POP clients have an option to leave mail on server after download, e-mail clients using POP generally connect, retrieve all messages, store them on the user’s PC as new messages, delete them from the server, and then disconnect. This keeps all your messages on your home computer.
E-mail clients using IMAP generally leave messages on the server until the user explicitly deletes them. This and other characteristics of IMAP operation allow multiple devices to manage the same mailbox. So if you plan on checking your email at home computer and on your phone or tablet, IMAP will allow you access your messages seamlessly across multiple devices.
- ‘Unlimited’ storage capacity on your local machine
- Easy to use
- Emails are stored only in one place
- Messages can be split across multiple devices
- Manage your email across multiple devices
- Messages stored on server are easier to recover if devices fail
- Can run into issues with storage capacity on the server if messages are no properly managed
- More bandwidth intensive (if you are on a data plan, this could eat up your usage)