Disclaimer:
This howto is tested on Ubuntu 16, 18, 20 and Debian 10, 11 edition.
Installing and configuring postfix
Step 1 » Assign static IP and hostname and add a host entry for the host name .
Assign hostname in /etc/hostname
mail.tweenpath.net
Add a host entry in /etc/hosts
192.168.1.10 mail.tweenpath.net
Step 2 » Update the repositories.
tweenpath@mail:~$ sudo apt-get update
Step 3 » Install postfix and dependencies . Press enter for all prompted questions during installation. we will do that in the next step.
tweenpath@mail:~$ sudo apt-get install postfix
Step 4 » After installation issue the below command to configure postfix.
tweenpath@mail:~$ sudo dpkg-reconfigure postfix
Now you will be prompted for set of details . choose the following values and replace tweenpath.net with your domain name.
1. Internet Site 2. tweenpath.net 3. tweenpath 4. tweenpath.net, localhost.localdomain, localhost 5. No 6. 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 192.168.0.0/24 7. 0 8. + 9. all
Step 5 » Now configure Postfix for SMTP-AUTH using Dovecot SASL by adding the below lines to postfix config file /etc/postfix/main.cf .
home_mailbox = Maildir/ smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_local_domain = smtpd_sasl_security_options = noanonymous broken_sasl_auth_clients = yes smtpd_sasl_auth_enable = yes smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination smtp_tls_security_level = may smtpd_tls_security_level = may smtp_tls_note_starttls_offer = yes smtpd_tls_loglevel = 1 smtpd_tls_received_header = yes
Step 6 » Now generate a digital certificate for tls. Issue the commands one by one and provide details as per your domain.
tweenpath@mail:~$ openssl genrsa -des3 -out server.key 2048 tweenpath@mail:~$ openssl rsa -in server.key -out server.key.insecure tweenpath@mail:~$ mv server.key server.key.secure tweenpath@mail:~$ mv server.key.insecure server.key tweenpath@mail:~$ openssl req -new -key server.key -out server.csr tweenpath@mail:~$ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt tweenpath@mail:~$ sudo cp server.crt /etc/ssl/certs tweenpath@mail:~$ sudo cp server.key /etc/ssl/private
Step 7 » Now configure certificate path
tweenpath@mail:~$ sudo postconf -e 'smtpd_tls_key_file = /etc/ssl/private/server.key' tweenpath@mail:~$ sudo postconf -e 'smtpd_tls_cert_file = /etc/ssl/certs/server.crt'
Step 8 » Open /etc/postfix/master.cf file and uncomment below lines to enable smtps ( 465 ) and submission ( 587 )
submission inet n - - - - smtpd -o syslog_name=postfix/submission -o smtpd_tls_security_level=encrypt -o smtpd_sasl_auth_enable=yes -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o milter_macro_daemon_name=ORIGINATING smtps inet n - n - - smtpd -o syslog_name=postfix/smtps -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes -o smtpd_relay_restrictions=permit_sasl_authenticated,reject -o milter_macro_daemon_name=ORIGINATING
Step 9 » Now install Dovecot SASL by typing the below command.
tweenpath@mail:~$ sudo apt-get install dovecot-common
Issue the following values for the prompts during installation.
1. yes 2. mail.tweenpath.net
Step 10 » Make changes to the files as follows.
Open /etc/dovecot/conf.d/10-master.conf file and find # Postfix smtp-auth line ( line no:95 ) and add the below lines .
# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0660
user = postfix
group = postfix
}
Open /etc/dovecot/conf.d/10-auth.conf file and find (line no:100)
auth_mechanisms = plain and replace auth_mechanisms = plain login
Step 11 » Restart postfix and dovecot services
tweenpath@mail:~$ sudo service postfix restart tweenpath@mail:~$ sudo service dovecot restart
Step 12 » Now test SMTP-AUTH and smtp/pop3 port access .
Type the below command and should get below response.
tweenpath@mail:~$ telnet mail.tweenpath.net smtp Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 mail.tweenpatha.net ESMTP Postfix (Ubuntu)
Now type ehlo mail.tweenpath.net and should get below response , please make sure you get those bolded lines .
ehlo mail.tweenpath.net 250-mail.tweenpath.net -------- 250-STARTTLS 250-AUTH PLAIN LOGIN 250-AUTH=PLAIN LOGIN --------- 250 DSN and try the same with port 587 (telnet mail.tweenpath.net 587). Postfix configuration is over, continue for dovecot installation. » Installing and configuring dovecot
Step 12 » Install dovecot using the below command
tweenpath@mail:~$ sudo apt-get install dovecot-imapd dovecot-pop3d
Step 13 » Now configure mailbox. Open /etc/dovecot/conf.d/10-mail.conf file and find (Line no:30 )
mail_location = mbox:~/mail:INBOX=/var/mail/%uReplace with mail_location = maildir:~/Maildir
Step 14 » Now change pop3_uidl_format . Open /etc/dovecot/conf.d/20-pop3.conf file and find and uncomment the below line ( Line no : 50 )
pop3_uidl_format = %08Xu%08Xv
Step 15 » Now enable SSL . Open /etc/dovecot/conf.d/10-ssl.conf file and find and uncomment the below line ( Line no : 6 )
ssl = yes
Step 16 »Restart dovecot service.
tweenpath@mail:~$ sudo service dovecot restart
Step 17 » Now test pop3 and imap port access using the telnet command.
tweenpath@mail:~$ telnet mail.tweenpath.net 110 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. +OK Dovecot (Ubuntu) ready. Repeat the same for 995,993,143 ports.
OR check for listening ports using netstat command .
tweenpath@mail:~$ netstat -nl4 you should get the result like below.
Step 18 » Create some users and check using mail clients like thunderbird or outlook
tweenpath@mail:~$ sudo useradd -m bobby -s /sbin/nologin tweenpath@mail:~$ sudo passwd bobby
Now mail server is ready, you can send and receive mail using the server. Continue for squirrelmail ..
» Installing and configuring squirrelmail
Step 19 » Install squirrelmail using the below command. This will install apache and PHP packages.
tweenpath@mail:~$ sudo apt-get install squirrelmail
Step 20 » Configure squirrelmail
tweenpath@mail:~$ sudo squirrelmail-configureEverything is pre-configured , we just need to change Organization name .
» Press 1 (Organization Preferences) » again press 1 (Organization Name) » Organization Name » Press S » Press Q to quit
Step 19 » Now configure apache to enable squirrelmail .
tweenpath@mail:~$ sudo cp /etc/squirrelmail/apache.conf /etc/apache2/sites-available/squirrelmail.conf tweenpath@mail:~$ sudo a2ensite squirrelmail
Step 20 » Restart Apache service
tweenpath@mail:~$ sudo service apache2 restart
Step 21 » Now open http://serverIP/squirrelmail in your browser and login using username (bobby) . you can send and receive mail using squirrelmail.
Ref:
https://www.krizna.com/ubuntu/setup-mail-server-ubuntu-14-04/amp/
https://help.ubuntu.com/community/PostfixAmavisNew
