BUOC 1:
Cai dat cau hinh POSTFIX
===================================
myhostname = mail.concung.com
mydomain = concung.com
myorigin = $mydomain
inet_interfaces = all
mynetwork = 172.16.84.0/24 127.0.0.0/8
home_mailbox = Maildir/
===================================
BUOC 2: CAI DAT DOVECOT

/etc/dovecot/conf.d/10-mail.conf
*****************************************
mail_location = maildir:~/Maildir
*****************************************
/etc/dovecot/conf.d/20-pop3.conf
*****************************************
pop3_uidl_format = %08Xu%08Xv
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
*****************************************
/etc/dovecot/dovecot.conf
*******************************************
protocols = imap pop3 lmtp
disable_plaintext_auth=no
*******************************************
#service dovecot restart
#chkconfig --level 35 dovecot on
Buoc 3: CAI DAT VA CAU HINH MOD_SSL (https)
#yum install mod_ssl
#cd /etc/pki/tls/certs
#make server.key ===>Nhap password is : p@ssw0rd
#openssl rsa -in server.key -out server.key ===>nhap password is : p@ssw0rd
#root@mail certs# make server.csr
******************************************************************
Enter password is : p@ssw0rd
Country Name (2 letter code): vn
State or Provice Name (Full Name): hcmcity
Locality Name (eg, city) : hcmcity
Organization Name(eg, company): lytutrongcollege
Organization Unit (eg, section): khoacnttltt
Common Name (eg, your name or your server's hostname : www.concung.com
Mail address: ltthcm@gmail.com
others: bo trong !!!!
********************************************************************
#openssl x509 -in server.csr -out server.crt -req -signkey server.key -days 3650
CAU HINH httpd.conf voi noi dung sau:
/etc/httpd/conf.d/ssl.conf
***********************************************
DocumentRoot "/var/www/html"
ServerName www.concung.com:443
SSLCertificateFile /etc/pki/tls/certs/server.crt
SSLCertificateKeyFile /etc/pki/tls/certs/server.key
***********************************************

BUOC 4: CAI DAT SQUIRRELMAIL
#yum install epel-release
#yum install squirrelmail
/etc/httpd/conf.d/squirrelmail.conf
***********************************************
Alias /webmail /usr/share/squirrelmail
<Directory "/usr/share/squirrelmail/plugins/squirrelspell/modules">
Deny from all
</Directory>

<Directory /usr/share/squirrelmail>
RewriteEngine on
RewriteCond %{HTTP} !=on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST}
</Directory>
*************************************************
#service httpd restart
#service iptables stop
#setsebool httpd_can_network_connect=1 (HERE !!!!) This will add the change to your /etc/selinux/targeted/booleans file and will be applied at each reboot
#setsebool -P httpd_can_sendmail 1
BƯỚC 5 : TEST KET QUA TỪ MÁY XP PROFESSIONAL

--------------------------------------------the end !-----------------------------------------------------------
1- Huong dan cau hinh mail Postfix,devecot, squirrelmail

Link:
https://support.rackspace.com/how-to/dovecot-installation-and-configuration-on-centos/

2-How To Configure a Mail Server Using Postfix, Dovecot, MySQL, and SpamAssassin
Link:
https://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassassin

3-How to config squirrelmail:
https://www.rosehosting.com/blog/how-to-install-squirrelmail-on-centos-7/
Buoc 1: yum -y install epel-release
Buoc 2: yum -y install squirrelmail

4-Thiet lap thong so boolean SElinux
https://www.certdepot.net/selinux-use-boolean-settings/

Ghi chu: Noi dung file cau hinh /etc/httpd/conf.d/squirrelmail.conf nhu sau
==============================================================================
Alias /webmail /usr/share/squirrelmail

<Directory "/usr/share/squirrelmail/plugins/squirrelspell/modules">
  Deny from all
</Directory>

# this section makes squirrelmail use https connections only, for this you
# need to have mod_ssl installed. If you want to use unsecure http
# connections, just remove this section:
<Directory /usr/share/squirrelmail>
  RewriteEngine  on
#  RewriteCond    %{HTTPS} !=on
#  RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</Directory>
==============================================================================
#service iptables stop
#setsebool httpd_can_network_connect=1 (HERE !!!!) This will add the change to your /etc/selinux/targeted/booleans file and will be applied at each reboot
#setsebool -P httpd_can_sendmail 1

/etc/hosts
ip	domainname	hostname
/etc/sysconfig/network
hostname <computer_name>
HUONG DAN CAI DAT VA THIET LAP SQUIRRELMAIL