mailServer

Step 1 – Set Up the Hostname

Next, you will need to set the hostname of your server. In this case, we will set the hostname to mail.example.com, as shown below:

hostnamectl set-hostname email.example.com

Next, open /etc/hosts file and bind your server IP address with the hostname:

nano /etc/hosts

Add the following line:

your-server-ip   email.example.com email

Save and close the file. Then, run the following command to apply the configuration changes:

hostname -f

Step 2 – Install Apache, MariaDB and PHP

Roundcube requires Apache, MariaDB and PHP to be installed on your server. You can install them with the following command:

apt-get install apache2 mariadb-server php libapache2-mod-php php-mysql -y

After installing all the required packages, you will need to enable the Apache rewrite module for Roundcube to work. You can enable it with the following command:

a2enmod rewrite

Next, reload the Apache service to apply the changes:

systemctl restart apache2

Step 3 – Install Let’s Encrypt SSL Certificate

Next, you will need to install the Let’s Encrypt Free SSL certificate on your server to configure your mail server with TLS.

First, install the Certbot client in your server with the following command:

apt-get install python-certbot-apache -y

Next, download the Let’s Encrypt Free SSL certificate for your domain email.example.com with the following command:

certbot certonly --apache -d email.example.com

This command will download the certificate in the /etc/letsencrypt/live/email.example.com/ directory.

Step 4 – Install and Configure Postfix

Next, let’s start to install a Postfix mail server with the following command:

apt-get install postfix

You will be redirected to the following screen:

Select Internet Site and press TAB and Enter to continue. You should see the following screen:

Provide your domain name and hit Tab and Enter to finish the installation.

The default Postfix configuration file is located at /etc/postfix/main.cf. Before configuring Postfix, it is recommended to back up this file:

mv /etc/postfix/main.cf /etc/postfix/main.cf.bak

Next, create a new Postfix configuration file as shown below:

nano /etc/postfix/main.cf

Add the following lines:

alias_database = hash:/etc/aliases

Save and close the file.

Next, you will need to define your domain in the /etc/postfix/virtual_mailbox_domains file:

nano /etc/postfix/virtual_mailbox_domains

Add the following line:

example.com #domain

Save and close the file then convert the file to a format that Postfix can understand with the following command:

postmap /etc/postfix/virtual_mailbox_domains

Next, edit the Postfix master configuration file:

nano /etc/postfix/master.cf

Uncomment the following line:

submission inet n   -   y   -   -   smtpd

Save and close the file when you are finished.

Step 5 – Install and Configure Dovecot

Next, you will need to install Dovecot with other required packages. You can install them using the following command:

apt-get install dovecot-core dovecot-imapd dovecot-pop3d dovecot-lmtpd -y

Next, you will need to define the Dovecot mail location to communicate with Postfix and virtual mailbox domains. You can define it by editing /etc/dovecot/conf.d/10-mail.conf file:

nano /etc/dovecot/conf.d/10-mail.conf

Find the following line:

mail_location = mbox:~/mail:INBOX=/var/mail/%u

And replace it with the following:

mail_location = maildir:/var/mail/vhosts/%d/%n

Save and close the file.

Next, create the Dovecot vhosts directory and the sub-directory for your domain name.

mkdir /var/mail/vhosts/example.com

Next, create a vmail user and a group, and assign the ownership of the directories to the vmail user.

chown -R vmail:vmail /var/mail/vhosts/

Next, edit the Dovecot master configuration file and enable IMAP and POP3 secure services:

nano /etc/dovecot/conf.d/10-master.conf

Find the following lines:

  }

And replace them with the following:

  }

On the same file, find the following lines:

  }

And replace them with the following:

  }

Next, find the following lines:

}

And replace them with the following:

}

Next, find the following lines:

}

And replace them with the following:

}

Save and close the file when you are finished.

Next, set up the Dovecot authentication process by editing the file /etc/dovecot/conf.d/10-auth.conf:

nano /etc/dovecot/conf.d/10-auth.conf

Uncomment the following line:

disable_plaintext_auth = yes

On the same file, find the following line:

auth_mechanisms = plain

And replace it with the following:

auth_mechanisms = plain login

Next, comment out the following line to disable the default Dovecot behaviour for authenticating users.

#!include auth-system.conf.ext

Next, uncomment the following line to enable password file configuration.

!include auth-passwdfile.conf.ext

Save and close the file when you are finished.

Next, edit the /etc/dovecot/conf.d/auth-passwdfile.conf.ext  file:

nano /etc/dovecot/conf.d/auth-passwdfile.conf.ext

Change the file as shown below:

}

Save and close the file.

Next, create a password file for the user you want to assign an email account:

nano /etc/dovecot/dovecot-users

Add the following lines:

admin@example.com:admin@123

Save and close the file.

Step 6 – Configure Dovecot to Use Let’s Encrypt SSL

Next, you will need to configure Dovecot to work with SSL. You can do it by editing the file /etc/dovecot/conf.d/10-ssl.conf:

nano /etc/dovecot/conf.d/10-ssl.conf

Find the following line:

ssl = yes

Replace it with the following:

ssl = required

Next, find the following lines:

#ssl_key = </etc/dovecot/private/dovecot.pem

And replace them with the following:

ssl_key = </etc/letsencrypt/live/email.example.com/privkey.pem

Save and close the file when you are finished, then restart the Postfix and Dovecot services to apply the configuration changes:

systemctl restart dovecot

Step 7 – Install and Configure Roundcube

By default, Roundcube is available in the Ubuntu 18.04 default repository. You can install it by just running the following command:

apt-get install roundcube

During the installation, you will be prompted to configure the database. Choose your desired option and hit Enter to finish the installation.

Next, you will need to configure the Apache virtual host for Roundcube. You can do it by editing the file /etc/apache2/sites-enabled/000-default.conf:

nano /etc/apache2/sites-enabled/000-default.conf

Change the file as shown below:

</VirtualHost>

Save and close the file, then restart the Apache web service to apply the changes:

systemctl restart apache2

Step 8 – Access Roundcube Webmail

Now, open your web browser and type the URL hhttp://email.example.com/mail. You will be redirected to the Roundcube login page:

Provide your username and password which you have defined in the Dovecot password file and click on the Login button. You should see the Roundcube default dashboard in the following page:

Conclusion