What are the differences between IMAP and POP?
Both IMAP (Internet Message Access Protocol) and POP (Post Office Protocol) are ways to access email messages that are stored on a mail server such as the Calmail server on the Berkeley campus. IMAP can do everything that POP can do and more. However, it does some functions differently from POP, and these differences have an impact on how you use your email software (such Thunderbird). With POP, all messages are stored in a single location on the server. When your email program retrieves messages using POP, all messages are downloaded to your computer. Depending on how your software is configured, the messages may be automatically removed from the server when your retrieve them or they may be left on the server. If you have multiple mailboxes and your mail software is using POP, those mailboxes exist just on your computer. That is why if you retrieve your messages from multiple locations, the mailboxes you have on the different computers will not be the same.
