Managing IMAP

IMAP and POP: A Comparison

If you look at which mail access protocols have popular market share, there are only two players on the field: POP and IMAP. POP essentially created the market. It also created a need for a protocol with a great many more features. IMAP filled that need.

POP

POP is the granddaddy of standardized mail access protocols. Although recently you could say that there was more POP client software than IMAP client software, now you can say only that there’s more well-implemented POP client software than well-implemented IMAP client software. Therein lies the continuing value of POP: its simplicity. POP is a humble protocol. It doesn’t keep track of a variety of message states, it doesn’t allow the user to search through her mailbox, and it doesn’t even facilitate storing messages in a number of mailboxes. It does one thing and one thing only: it makes the messages available to the user to download to her local machine on demand.

For some users, the limitations of POP are just fine. They use one and only one machine to read their mail, and they download all the messages from their mail server to that one machine and subsequently delete them from the server. In the early days of POP, users wanting to read their mail from more than one machine would have found themselves downloading duplicate copies for their email to each machine from which they wanted to view that mail. At some point, when they thought all the various machines had caught up with their new ...