The Mail Application protocol includes :
- Simple Mail Transfer Protocol (SMTP), which is used to send or relay outgoing e-mails, consumes TCP 25 ports.
- The third version of the Post Office Protocol (POP3), which stores messages on the server to a local host, consumes TCP 110 ports.
- The fourth edition of the Internet Information Access Protocol (IMAP4), which is used to access messages on localhost, consumes TCP 143 ports.
To build an enterprise-Class e-mail system, consider the following points:
anti-spam and anti-virus modules: Prevents spam or virus messages from interfering with the corporate mailbox.
Message Encryption: Ensure that the contents of the message are not sniffed or tampered with.
Email Monitoring Audit: Monitor all staff e-mails with or without sensitive words, disclose enterprise information, etc.
Stability: Good anti-DDoS attack ability, ensure system online rate and so on.
Deploy the basic e-mail system
Separate use of the Postfix service program does not allow users to complete the operation of sending and receiving mail, because a basic e-mail system requires at least SMTP server, Pop3/imap server
Configure Local Host Name
[Email protected] ~]# vim/etc/hostname mail.scott.com
Add a record and MX record
See using bind to build a DNS service
To provide a user with an e-mail system for the Scott domain , you need to add a and MX records to the DNS server first:
Modify the DNS address of this computer
cat /etc/192.168. 0.85
Configuring the Postfix service Program
To stop the iptables firewall:
The Postfix postoffice service is installed by default in Red Hat RHEL7 system:
Yum Installpostfixloaded plugins:langpacks, product-ID, subscription-Managerrhel7|4.1Kbxx:xx(1/2): Rhel7/group_gz |134Kbxx:xx(2/2): rhel7/primary_db |3.4MBxx:xx Package2:p ostfix-2.10.1-6. el7.x86_64 already installed and latest versionnothing to Do
the configuration file for the Postfix Post Office service program is as follows:
File |
Role |
/usr/sbin/postfix |
Main Service Program |
/etc/postfix/master.cf |
The configuration file for the Master Master program. |
/etc/postfix/main.cf |
The configuration file for the Postfix service. |
/var/log/maillog |
Logs that record the message delivery process. |
1th step: View the Postfix service Program Master profile:
Edit the main configuration file of the Postfix service (modify the 5 parameters, and also need to remove the number (#) before the parameter to take effect):
[Email protected]~] # vim/etc/postfix/main.cf// Modify the postoffice hostname on line 76th. myhostname = mail.scott.com// Modify the postoffice domain name on line 83rd. mydomain = scott.com// Modify the outgoing mail domain name of line 99th, the value of $mydomain is defined above. myorigin = $mydomain// Modify the Listening network card on line 116th. inet_interfaces = all// modifies the host name and domain name of the receiving message on line 164th. mydestination = $myhostname, $mydomain
2nd step: Create a Post Office account:
[Email protected]~] # useradd Boss[[email protected]echo"123456" passwd --forpasswd: All authentication tokens updated successfully.
3rd step: Start the Postfix service program:
[[Email protected]~] # systemctl restart Postfix[[email protected]~] # Systemctl enable Postfix LN ' /usr/lib/systemd/system/postfix.service ' ' /etc/systemd/system/multi-user.target.wants/postfix.service '
Now let's test whether postfix can send mail, as follows:
In the QQ mailbox view:
If you do not find the domain to remember to join the QQ mailbox whitelist.
Configuring the Dovecot Service Program
1th Step: Install the Dovecot service program:
Yum Install dovecot-yloaded plugins:langpacks, product-ID, subscription-1 :2.2. 43.2 for2.3. 3.4-one528 k ........... Omit part of the installation process ...... ..... Complete!
2nd Step: Modify the Dovecot program master configuration file:
[Email protected]~] # vim/etc/dovecot/dovecot.conf// Modify Support Post Office Protocol for Line 24th. protocols = IMAP POP3 LMTP// then additional allow clear text authentication (25 lines). Disable_plaintext_auth = no// modifies the address of the allowed login segment on line 48th, all allowed is (0.0.0.0/0). 192.168. 0.0/
3rd Step: Configure the format and storage path of the message. <
Edit the Dovecot configuration file (remove the comment (#号) from line 25th):
[Email protected]~] # vim/etc/dovecot/conf.d/-= mbox:~/mail:inbox=/var/mail/%u
4th step: Create the storage directory for the message:
su -login:1 onpts/ mkdir -P Mail/.imap/inbox
5th step: Start the Dovecot service program:
[[Email protected]~] # systemctl restart Dovecot[[email protected]~] # Systemctl enable Dovecot LN ' /usr/lib/systemd/system/dovecot.service ' ' /etc/systemd/system/multi-user.target.wants/dovecot.service '
Users use the Post Office system
Modify the DNS address of the client to a local DNS server address
Log in to the boss user in Foxmail
Send a message to the root user with the user
Log in to root user, check email:
[Email protected] ~]# mailheirloom Mail version12.5 7/5/Ten. Type? forHelp ...... >n7[Email protected] Thu Jan + -: A -/1580 "Test"N8[Email protected] Thu Jan + -:Wuyi $/1743 "Test Message"&8Message8: From [email protected] Thu Jan + -:Wuyi: $ .Return-path: <[email protected]>X-original-to : [Email protected]delivered-to: [Email Protected]date:thu, +Jan . -: Wu:xx+0800From :"[email protected]"<[email protected]>To:root<[email protected]>Subject: Test message x-priority:3X-has-Attach:nox-mailer:foxmail7,2,7, +[Cn]content-type:multipart/Alternative; Boundary="----=_001_nextpart160336538781_=----"status:rcontent-type:text/Plain; CharSet="GB2312"If you receive this email, it will be successful on behalf of the Post Office system. [Email protected]
Send and receive emails using postfix and Dovecot