Marco Linux Learning note Five--mail service

1.SMTP is only responsible for sending mail to the server, other, such as identity authentication detection mail, can not be completed. (25/TCP)

esmtp:extended SMTP

Pop3:post Office Protocol

Imap4:internet Mail Access Protocol

2.Open Relay: Open relay

It is someone else's mail from this mail server, you all help forward, this will become the source of spam. So you have to close the open Relay

3.sasl,simple authintication secure layer, simple authentication security layers

Used to help SMTP authenticate.

4.POP3 protocol, which specifies how users can retrieve their mail from the mailbox and pass it on to the user.

Or use Mra,mail retrieval agent, Mail Retrieval (retrieve) proxy. Can be seen as a server.

As you can see, the message is delivered with SMTP, and the POP3 is used to retrieve the message.

5.Web Mail

Most of the time, we use Broswer to send and receive emails. So can the Web be used to send and receive mail?

Broswer as a user to edit the message editor, and can pass the user password to the POP3 server process, authenticate, take the user's mail.

6.ldap,lightweight Directory Access Protocol, Lightweight directory accesses protocol

When the number of users is very fast, we detect the input username and password is not the server, we can not put all the user name and password into memory, so we have to use a database server to detect is not. MySQL can be used, but the LDAP protocol is faster and SQL Server consolidates LDAP.

7. Virtual Users

A digital ID that is used only to access a service. He is not a system user and cannot be used to function as other things.

8.MTA, Mail transfer agent, SMTP server

SendMail software, qmail, Postfix, Exim, Exchange

9.postfix, modular design, and safe, with sendmail compatibility is very good, high efficiency.

MDA, mail delivery Agent

Procmail, Maildrop

MRA, mail search agent (POP3 or IMAP4 protocol)

Cyrus-imap Software, Dovecot

MUA, mail user agent

Outlook,foxmail,thunderbird,evolution,mutt (Text interface)

Webmail:

Openwebmail, Squairrelmail, Extmail

SASL: Certification framework, to really achieve certification also need to install the certification mechanism

CYRUS-SASL, Courier-authlib

15. Implement a mail server:

The framework of the outgoing mail server can be used: postfix+sasl+mysql

Email Framework by: Dovecot (which itself can be certified) +mysql

Webmail:extmail+extmail+httpd