POP3 vs. IMAP4
From mail2web.com Wiki
What is the difference between POP3 and IMAP4?
POP3 and IMAP4 are two different protocols through which email is delivered from a server to a client. IMAP4 is a newer email protocol and, as such, is generally less common than POP3. The primary difference between the two is that the IMAP4 protocol allows email messages to be manipulated (e.g., categorized into folders) on the email server, while with the POP3 protocol, such messages can only be manipulated once they are downloaded to the client.
To access IMAP4-based email servers, please use mail2web.com's Advanced Login.