POP and IMAP are two different protocols, or ways of accessing your email account. The main difference between them is that:
- By default, IMAP stores messages on the server.
- By default, POP downloads messages to your computer or device and deletes them from the server.
ACCC strongly recommends using IMAP:
- Most UIC faculty, staff and students access their email accounts from multiple computers and devices, IMAP is designed to retain messages on the server so that they remain accessible to multiple email clients and devices.
- With IMAP, you can store messages in email folders, which accessible from any email client or device that uses IMAP. POP can only access your Inbox.
- With IMAP, you can configure different email clients (Webmail, Mozilla Thunderbird, iPhone, Android) to use the same special folders (Sent Messages, Drafts, etc.) so that the draft of a message composed in your desktop email client can be finished and sent from your mobile client.
While POP has an option to leave mail on server (LMOS), it is essentially imitating IMAP. If you prefer to leave a copy of messages to be accessible to other clients and devices, simply use IMAP. If you use IMAP and prefer to keep a local copy of all messages, check the configuration of your email client to keep copies of messages for offline viewing.