Windows Server 2003 mail full introduction (i)

The whole mail system is mainly composed of electronic post Office system and e-mail sending and receiving system. The email send and receive system is called MUA. An electronic post Office system is called an MTA.

(1) MUA: When the message is written, you should use the MUA (mail user agent, mail users Agents) program to send the message to a isp,mua on the internet is a mail system client program, MUA use the SMTP protocol to "push" user letters to the MTA; When a user receives a message, a POP or IMAP protocol is used to send a user message from the target MTA to the Mua,mua with at least 3 features: Compose a message, display a message, and process a message.

(2) MTA. The delivery of an e-mail message depends on the MTA (mail Transfer agent, message transfer agent) to complete. As a server-side program for messages, it is responsible for storing and forwarding messages. It has the following functions: accepting and passing messages sent by the client; maintaining the message queue so that clients do not have to wait until the message is actually sent, receive the customer's message, and place the message in the buffer store until the user connects to receive the message. Optionally forwards and rejects the message that the received destination is another host.

e-mail system combined with DNS

When a mail server program receives a message to be sent, it first needs to determine which server to post the letter based on the destination address, which is implemented through the DNS service and resolves the e-mail domain, MX, and A records with two DNS resource records. The MX record enables you to associate an e-mail domain with the FQDN of one or more mail servers that provide services for that domain, informing the MTA where to deliver the message. Each SMTP server referenced by an MX record must have a record of a A. A record maps the specified FQDN to its IP address. You can set different priority levels in more than one MX record in a domain. The smaller the priority, the higher.

Deploying E-mail Services

This is installed by adding or removing programs.

First configure DNS for its resolution.

Create a record of the e-mail server in the forward lookup zone Landon.con to enable resolution of the FQDN of the e-mail server.