How to Host Your Own Webmail with Roundcube

• Postfix: An open-source mail transfer agent (MTA) that handles sending and receiving emails using SMTP.

• Dovecot: An open-source IMAP and POP3 server that manages email retrieval and storage, allowing users to access their emails securely.

• Roundcube: A web-based email client that provides a user-friendly interface for managing emails via a browser.

  Perquisites

  Domain name pointed to your VPS IP address.

Step 1 : Set up the Hostname

hostnamectl set-hostname <hostname> 

• Open /etc/hosts file and bind your server IP address with the hostname:

nano /etc/hosts

• Add the following line:

your-server-ip   <hostname>

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

hostname -f

Step 2 : Install Apache, MariaDB & 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

• 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:

add-apt-repository ppa:certbot/certbot
apt-get update -y
apt-get install python-certbot-apache -y

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

certbot certonly --apache -d <hostname>

Step 4 : Install and Configure Postfix

apt-get install postfix

• You will be redirected to the screen. Select Internet Site for General type of mail configuration. Povide 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

• Create a new Postfix configuration file as shown below:

  nano /etc/postfix/main.cf
  

• Add the following lines:

  # GENERAL SETTINGS
  smtpd_banner = $myhostname ESMTP $mail_name
  biff = no
  append_dot_mydomain = no
  readme_directory = no
  # SMTP SETTINGS
  smtp_use_tls=yes
  smtp_tls_security_level = may
  smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
  # SMTPD SETTINGS
  smtpd_use_tls=yes
  smtpd_tls_security_level = may
  smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
  smtpd_tls_cert_file=/etc/letsencrypt/live/email.example.com/fullchain.pem
  smtpd_tls_key_file=/etc/letsencrypt/live/email.example.com/privkey.pem
  smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated,  reject_unauth_destination
  # SASL SETTINGS
  smtpd_sasl_auth_enable = yes
  smtpd_sasl_type = dovecot
  smtpd_sasl_path = private/auth
  # VIRTUAL MAIL BOX AND LMTP SETTINGS
  virtual_transport = lmtp:unix:private/dovecot-lmtp
  virtual_mailbox_domains = /etc/postfix/virtual_mailbox_domains
  # OTHER SETTINGS
  myhostname = email.example.com
  myorigin = /etc/mailname
  mydestination =  localhost.$mydomain, localhost
  relayhost =
  mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
  mailbox_size_limit = 0
  recipient_delimiter = +
  inet_interfaces = all
  inet_protocols = all
  alias_maps = hash:/etc/aliases
  alias_database = hash:/etc/aliases
  

• Save and close the file.
• Define your domain in the /etc/postfix/virtual_mailbox_domains file:

  nano /etc/postfix/virtual_mailbox_domains
  

• Add the following line:

  soc.test.lab.ac.in #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
  

• 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

• Install Dovecot with other required packages

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

• Define the Dovecot mail location to communicate with Postfix and virtual mailbox domains.

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

• Find the following line:

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

Replace it with

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

Save and close the file.

• Create the Dovecot vhosts directory and the sub-directory for your domain name.

mkdir /var/mail/vhosts
mkdir /var/mail/vhosts/example.com

• Create a mail user and a group, and assign the ownership of the directories to the vmail user.

groupadd -g 5000 vmail
useradd -r -g vmail -u 5000 vmail -d /var/mail/vhosts -c "virtual mail user"
chown -R vmail:vmail /var/mail/vhosts/

• 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:

  inet_listener imaps {
      #port = 993
      #ssl = yes
  }
  

And replace them with the following:

inet_listener imaps {
    port = 993
    ssl = yes
  }

On the same file, find the following lines:

inet_listener pop3s {
    #port = 995
    #ssl = yes
  }

And replace them with the following:

inet_listener pop3s {
    port = 995
    ssl = yes
  }

Next, find the following lines:

service lmtp {
unix_listener lmtp {
#mode = 0666
}

And replace them with the following:

service lmtp {
unix_listener /var/spool/postfix/private/dovecot-lmtp {
mode = 0600
user = postfix
group = postfix
}

Next, find the following lines:

service  auth {
  # Postfix smtp-auth
  #unix_listener /var/spool/postfix/private/auth {
  #  mode = 0666
  #}
}

And replace them with the following:

service auth {
...
#Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0666
user=postfix
group=postfix
}

Save and close the file when you are finished.

• Set up the Dovecot authentication process

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

• 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/

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:

passdb {
  driver = passwd-file
  args = scheme=PLAIN username_format=%u /etc/dovecot/dovecot-users
}
userdb {
driver = static
args = uid=vmail gid=vmail home=/var/mail/vhosts/%d/%n
}

Save and close the file.

• 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

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

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

And replace them with the following:

ssl_cert = </etc/letsencrypt/live/email.example.com/fullchain.pem
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 postfix
systemctl restart dovecot

Step 7 : Install and Configure Roundcube

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.

• 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 *:80>
        Alias /mail /usr/share/roundcube

        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html
        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

</VirtualHost>

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

systemctl restart apache2

Access your Roundcube Webmail

http://email.VISHALCHAND.com/mail.