POP3 is considered to be an obsolete version of the mail protocol. Therefore, it is recommended to use proxies that work via IMAP instead. These proxies are used only for reading emails that have already arrived in the user's mailbox. Another protocol - SMTP - is used for transferring mails.

POP3 and IMAP proxies are similar in their work principle. Still, the main difference is that using POP3 email, clients delete all messages from their server after they download them. In contrast, IMAP proxies store messages on their server. Not all emails are downloaded, but only those marked by the user. There is also a synchronization option. When a client downloads all saved emails from the server but doesn't delete them, they remain on the storage.

The main advantage of IMAP over POP3 is the advanced tools, which allows you to perform quite complex actions concerning mails and their sorting, such as template searching. It is possible to create several folders at once and move correspondences between them. And one more significant advantage over POP3 is the ability to use flags to distinguish read mail from unread mail.

The mailbox can be accessed by multiple devices that have access to the Internet. It doesn't matter if you use a smartphone or a computer. The mailbox will appear in the same view, and it is possible to execute several commands simultaneously. The storage space on the server is limited. Therefore, emails will have to be manually deleted from time to time to keep the mailbox from overflowing.

The IMAP protocol is more difficult to use. Still, it allows several devices to connect to the mailbox at once. Several commands can be logged out and executed simultaneously. This "multi-channel" approach makes proxies one of the most versatile and convenient for working with email.