Basic Email Server with Postfix, Dovecot and Squirrelmail on CentOS 6

Step 1 »Before installation assign a static ip and add a host entry for your domain to that IP in the /etc/hosts file like below.

Step 2 » Issue the below command to install postfix

[root@mail ~]# yum -y install postfix

Step 3 » Now issue the below command to install SMTP AUTH packages .

[root@mail ~]# yum -y install cyrus-sasl cyrus-sasl-devel cyrus-sasl-gssapi cyrus-sasl-md5 cyrus-sasl-plain

Postfix package installation is completed .

Step 4 » Issue the below commands one by one for creating SSL Cert.

[root@mail ~]# mkdir /etc/postfix/ssl
[root@mail ~]# cd /etc/postfix/ssl/
[root@mail ssl]# openssl genrsa -des3 -rand /etc/hosts -out smtpd.key 1024
[root@mail ssl]# chmod 600 smtpd.key
[root@mail ssl]# openssl req -new -key smtpd.key -out smtpd.csr
[root@mail ssl]# openssl x509 -req -days 365 -in smtpd.csr -signkey smtpd.key -out smtpd.crt
[root@mail ssl]# openssl rsa -in smtpd.key -out smtpd.key.unencrypted
[root@mail ssl]# mv -f smtpd.key.unencrypted smtpd.key
[root@mail ssl]# openssl req -new -x509 -extensions v3_ca -keyout cakey.pem -out cacert.pem -days 365

Step 4 » Now open /etc/postfix/ file

Find and comment the below lines

#inet_interfaces = localhost #---> line no 116
#mydestination = $myhostname, localhost.$mydomain, localhost #--> line no 164 and add these lines at the bottom of the file.
myhostname =
mydomain =
myorigin = $mydomain
home_mailbox = mail/
mynetworks =
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = cyrus
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtpd_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom

Step 5 » Now open /etc/postfix/ file and add the below line after smtp

smtps     inet  n       -       n       -       -       smtpd
      -o smtpd_sasl_auth_enable=yes
      -o smtpd_reject_unlisted_sender=yes
      -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
      -o broken_sasl_auth_clients=yes

Step 6 » Now start postfix and saslauthd service

[root@mail ~]# service postfix start
[root@mail ~]# service saslauthd start

» Issue the below commands to start the postfix and saslauthd at startup

[root@mail ~]# chkconfig --level 235 postfix on
[root@mail ~]# chkconfig --level 235 saslauthd on

Step 7 » Now check your smtp connectivity . just telnet localhost on port 25 and type this command ehlo localhost

[root@mail ~]# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 ESMTP Postfix
ehlo localhost <---- type this command
250-SIZE 10240000
250 DSN
221 2.0.0 Bye

Connection closed by foreign host.
If you get this output .. Great .. everything is fine till now.

Step 8 » Issue this command to install dovecot

[root@mail ~]# yum -y install dovecot

Step 9 » After installation open /etc/dovecot/dovecot.conf file and add the below line at the end of the file. please make sure mail_location and home_mailbox in postfix configuration are using the same name.

protocols = imap pop3
mail_location = maildir:~/mail
pop3_uidl_format = %08Xu%08Xv

Step 10 » Now start dovecot service

[root@mail ~]# service dovecot start

» Issue the below command to start the dovecot at startup

[root@mail ~]# chkconfig --level 235 dovecot on

Step 11 » Now test your pop3 connectivity .

[root@mail ~]# telnet localhost 110
Trying ::1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
+OK Logging out
Connection closed by foreign host.

Yes .. your server is ready to receive mails .

Step 11 » Now create users to test your configuration.

[root@mail ~]# useradd -m bobby -s /sbin/nologin
[root@mail ~]# useradd -m leela -s /sbin/nologin

and create passwords for the users created

[root@mail ~]# passwd bobby
[root@mail ~]# passwd leela

Step 12 » Test your configuration in thunderbird . Refer the below image for configuration details.

Step 13 » Now you can send and receive mails using this server. In case of any issues please check the log file /var/log/maillog )

your mail server is ready …

Step 14 » you need to add EPEL repository to install squirrelmail package. you can find latest EPEL repository rpm here ( )

[root@mail ~]# rpm -ivh

Step 15 » Issue the below command to install squirrelmail.

[root@mail ~]# yum install squirrelmail

This command will install squirrelmail along with apache and php.

Step 16 » Now run the below command to configure squirrelmail .

[root@mail ~]# perl /usr/share/squirrelmail/config/
»»» 1 »»» 1 »»» tweenpath (type Organization name ) »»» R ( return )
»»» 2 »»» 1 »»» ( hit space for empty Domain name ) and choose 3 »»» SMTP ( choose SMTP ) »»» R ( return )
»»» D »»» dovecot ( type ) »»» press enter with default
»»» s ( save and quit)

Step 17 » Open /etc/httpd/conf.d/squirrelmail.conf file and uncomment below lines

# RewriteCond %{HTTPS} !=on
# RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}

Step 18 » start apache service

[root@mail ~]# service httpd start

» Issue the below commands to start the httpd at startup

[root@mail ~]# chkconfig --level 235 httpd on

Step 19 » Now open http://serverip/webmail path in your browser . you could able to see the below page .



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