1. The POP3 protocol allows the email client to download emails on the server, but the operations on the client will not be fed back to the server, the operations on the client and the web version of the mailbox cannot be synchronized. The IMAP protocol provides two-way communication between the web mailbox and the mailbox client. The operations of the client will be fed back to the server. The operation of the client on the email will also keep the corresponding actions of the web mailbox.
2. In the POP3 protocol, it is easier to lose emails or download the same emails multiple times, while the IMAP protocol allows users to read offline. The summary browsing function provided by IMAP allows users to make a decision whether to download or not after reading all the email information.
3. IMAP better supports access to new emails at any time from multiple different devices.