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This article mainly explains "what is the authentication status of the imap protocol". The explanation in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "what is the authentication status of the imap protocol".

The IMAP protocol is used to develop email security products. Receiving mail using IMAP is very different from pop3. The imap protocol is more complex. Once the connection between the client and the server is established, an IMAP4rev1 connection will be in one of the four states. The initial state is identified in the welcome of the server. Most commands are correct only in a specific state. When the connection is in an inappropriate state, the client attempts an inappropriate command to cause a protocol error, and the server responds with a BAD or NO (depending on the server's implementation) command.

1. Uncertified status

In an unauthenticated state, the client must provide an authentication certificate before most commands are licensed. If a non-connection is pre-authenticated, when a connection starts, it enters an unauthenticated state.

2. Authentication status

In the authenticated state, the client is authenticated, and it must select a mailbox to access before the command that affects the message is licensed. When a pre-authenticated connection starts, the approved authentication certificate has been provided, after an error occurred in selecting a mailbox, or after a successful CLOSE command, the authentication state is entered.

3. Selected status

In a selected state, a mailbox is selected for access. When a mailbox is successfully selected, it enters this state.

4. Logout status

In the logged out state, the connection is being terminated. A client request (via the LOGOUT command), or a unilateral action by the client or server, can lead to this state.

If the client requests logout status, the server must send an untagged BYE response and a tagged OK response of the LOGOUT command before closing the connection; the client must read the tagged OK response of the LOGOUT command before closing the connection.

A server cannot unilaterally close a connection without sending an untagged BYE response with a reason. Instead of unilaterally closing the connection, a client should issue a LOGOUT command. If the server finds that the client has unilaterally closed the connection, the server can ignore the untagged BYE response and simply close its connection.

(1) connections that are not pre-authenticated (OK welcome)

(2) pre-authenticated connections (welcome to PREAUTH)

(3) rejected connection (BYE Welcome)

(4) successful LOGIN or AUTHENTICATE command

(5) successful SELECT or EXAMINE command

(6) CLOSE command, or failed SELECT or EXAMINE command

(7) LOGOUT command, the server is down, or the connection is closed

At present, most of the mail security products in the market are a closed mail system, and there is a problem that users give up the original account and use the new account in deployment, which leads to some difficulties in deployment. In the email transparent encryption products, Tianyu Yunan's secret mail is very novel. It uses a secure email gateway to transparently encrypt the email. Users are completely unaware of the existence of the email gateway, but the email is armored on the server, allowing you to hack into the server, but the email you see is a pile of garbled codes.

Thank you for your reading, the above is the content of "what is the authentication status of the imap protocol". After the study of this article, I believe you have a deeper understanding of the authentication status of the imap agreement, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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