Common mail service protocols: POP3, IMAP, EXCHANGE, and imapexchange

Common mail service protocols: POP3, IMAP, EXCHANGE, and imapexchange

Some time ago I did mailbox client development, involving protocol support issues. By the way, I learned several major protocols:

Generally, before setting up a mailbox on a mobile client, you 'd better know which protocol is supported by your mailbox. The common protocols include the following:

POP3, IMAP, and Exchange are described in the following three Protocols to understand the differences between them:

POP3 (Post Office Protocol) This Protocol is used to support remote management of emails on servers using clients. When this protocol is used, the client downloads the email from the server and then deletes the email from the server. The email address of this protocol is usually bound to a computer or machine, users cannot access emails from other places. The POP protocol is used to retrieve emails from the email server. However, most POP3 mail servers currently support the "Download only mail, server side does not delete" protocol-based POP3 protocol.

IMAP (Internet Message Access Protocol) is an application layer Protocol used to Access emails on a remote server from a local client. Therefore, POP3 and IMAP support access to server storage information from an email client. But more importantly, IMAP:

A. Supports connection and disconnection modes. When pop3 is used, the client only connects to the server for a period of time until it downloads all the information. In IMAP, as long as the user interface is active and the content of the downloaded information is required, the client will be connected to the server all the time. The connection method increases the response speed.

B. Multiple customers can access one mailbox at a time.

C. Partial access to messages is supported. For example, you can download the topic and the sender before opening the email address. When you view the details, download the details.

D. Message status information can be retained on the server.

E. You can access multiple mailboxes on the server.

F. server search is supported.

ExchangeIt is a complete set of email service components of Microsoft. In addition to the conventional SMTP/POP protocol services, it also supports IMAP4, LDAP, and NNTP protocols. Exchange Server is a message and collaboration system. Exchange server can be used to deploy enterprise, school email systems, or even free email systems.