Mail Server With Front-end and Database Support (Step-by-Step)

Table of Contents

Before proceeding you must be having advance knowledge of DNS, postfix, dovecot, networking, and Linux command line. We can use both rhel7 as well as CentOS7, but in our case, we are using CentOS7.

Install Required Packages

1. Update your system to the latest repository data.

# yum update

2. The version of Postfix included in the main CentOS repository does not include support for MariaDB, therefore, you will need to install Postfix from the CentOS Plus repository. Before doing so, add exclusions to the “[base]” and “[updates]” repositories for the Postfix package to prevent it from being overwritten with updates that do not have MariaDB support.

Your repository should look like below:

[base]
name=CentOS-$releasever - Base
exclude=postfix
#released updates
[updates]
name=CentOS-$releasever -
Updates exclude=postfix

3. For the database support, we are using “mariadb“.

4. Install the required packages.

# yum –enablerepo=centosplus install postfix

# yum install dovecot mariadb-server dovecot-mysql

# yum install bind bind-utils

**Check Information of a package using yum**

**Check postfix and dovecot is installed on not using yum**

Setup DNS Server

Your “/etc/named.conf” file should look exactly like this.

**Check local DNS configuration on Centos 7**

Create your zone files by navigating to “/var/named/” and the group of zone files to “named”.

Start your local dns server and check it.

# service named restart

# chkconfig named on

# nslookup mail.example.com ( it should return your machine’s ip )

Setup the MariaDB for Virtual Domains and Users – Mail server with front-end

Configure mariadb to start on boot, then start its service.

# systemctl enable mariadb

# systemctl start mariadb

2. After starting its service, run the following command:

# mysql_secure_installation

> set a root password ( in my case the password is ‘1’ )

> remove anonymous user accounts ( y )

> disable root logins outside of localhost ( y )

> remove test databases ( y )

> reload privilege tables ( y )

3. Start the mariadb shell.

# mysql -u root -p

4. Create a database for your mail server and switch to it.

> CREATE DATABASE mail;

> USE mail;

5. Create a mail administration user called “mail_admin” and grant it permissions on the “mail” database. Also, set password of your choice ( in our case password = password ).

> grant all on mail.* to ‘mail_admin’@’localhost’ identified by ‘password’;

> grant all on mail.* to ‘mail_admin’@’localhost.localdomain’ identified by ‘password’;

> flush privileges; ( don’t forget to run this command )

6. Create virtual domains table to store virtual domains.

> CREATE TABLE domains (domain varchar(50) NOT NULL, PRIMARY KEY (domain) );

**Check the Database entry for the domain**

7. Create a table to handle mail forwarding.

> CREATE TABLE forwardings (source varchar(80) NOT NULL, destination TEXT NOTNULL, PRIMARY KEY (source) );

8. Create users table.

varchar(20) NOT NULL, PRIMARY KEY (email) );

> CREATETABLE users (emailvarchar(80) NOTNULL, password

9. Create a transports table.

> CREATE TABLE transport ( domain varchar(128) NOT NULL default ”, transportvarchar(128) NOT NULL default ”, UNIQUE KEY domain (domain) );

10. Exit the mariadb shell.

> quit

11. Bind your MariaDB to localhost (127.0.0.1) by editing “/etc/my.cnf”, adding the following to the “[mysqld]” section of the file.

> bind-address=127.0.0.1

**Adding bind address to mysql conf file**

**This is required for Postfix to be able to communicate with the database server. If you have MariaDBset up to listen on another IP address (such as an internal IP), you will need to substitute this IP addressin place of 127.0.0.1 during the Postfix configuration steps. It is not advisable to run MariaDB on apublicly-accessible IP address.**

12. Restart your database server.

#systemctl restart mariadb

Next, We will be configuring the postfix so that it can communicate with our database.

Configure Postfix to Work With MariaDB – Mail server with front-end

1. Create a virtual domain configuration file for postfix called “/etc/postfix/mysql-virtual_domains.cf”.

2. Create a virtual forwarding file for Postfix called “/etc/postfix/mysql-virtual_forwardings.cf”.

**postifx mysql virtual forwardings config file**

3. Create a virtual mailbox configuration file for Postfix called “/etc/postfix/mysql-virtual_mailboxes.cf”.

4. Create a virtual email mapping file for Postfix called “/etc/postfix/mysql-virtual_email2email.cf”.

**postfix mysql virtual email to email config file**

5. Set proper permissions and ownership for these configuration files.

# chmod o= /etc/postfix/mysql-virtual_*.cf

# chgrp postfix /etc/postfix/mysql-virtual_*.cf

6. Create a user and a group for mail handling. All virtual mailboxes will be stored under this user’s home directory.

# groupadd -g 5000 vmail

# useradd -g vmail -u 5000 vmail -d /home/vmail -m

7. Complete the remaining steps required for Postfix configuration. Please be sure to replace “server.example.com” with the Host’s fully qualified domain name. If you are planning on using your own SSL certificate and key, replace “/etc/pki/dovecot/private/dovecot.pem” with the appropriate path to your ssl certificate.

8. Edit the file “/etc/postfix/master.cf” and add the Dovecot service to the bottom of the file.

Add dovecot support in postfix config file

9. Configure the postfix to start on boot and start it for the first time.

# systemctl enable postfix

# systemctl start postfix

Configure Dovecot

1. create a backup of your “dovecot.conf” file.

# mv /etc/dovecot/dovecot.conf /etc/dovecot/dovecot.conf-backup

2. Your dovecot file should look like this.

3. MariaDB will be used to store password information, so “/etc/dovecot/dovecot-sql.conf.ext” must be created. Insert the following contents into the file.