Dovecot is used to receive incoming emails on your server from Postfix. Dovecot is an open-source IMAP and POP3 Mail Server used for Linux and UNIX Operating Systems.

Following are the steps to install Dovecot on Centos.

We believe you have Postfix preinstalled. We are doing this configuration in Centos 6.

1. Install Dovecot using the below command.
   
   

   # sudo yum install dovecot

   
   
   
2. Once it is installed, you need to configure the dovecot file. Open in vi editors and make changes as below.
   
   

   # vi /etc/dovecot/dovecot.conf

   protocols = imap pop3
   mail_location =  maildir:~/Maildir

   
   
   

3. Now, we will configure the authentication process file at path /etc/dovecot/conf.d/10-auth.conf. Again use vi editor and uncomment the following line.
   
   

   auth_mechanisms = plain login

4. To configure email location, we will add below line in 10-mail.conf file at /etc/dovecot/conf.d/ location.
   
   

   mail_location = maildir:~/Maildir

   
   
   
5. Now, we will configure UNIX socket for Postfix SMTP AUTH. To do this we will modify the file /etc/dovecot/conf.d/10-master.conf and need to make changes as per the below image.
   
   

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

   #unix_listener auth-userdb {
        #mode = 0600
        #user =
        #group =
      #}
   
    # Postfix smtp-auth
      unix_listener /var/spool/postfix/private/auth {
        mode = 0666
        user = postfix
        group = postfix
      }

   
   
   

6. Open file 20-pop3.conf with below command.
   
   

   vi /etc/dovecot/conf.d/20-pop3.conf

7. Uncomment or add the below line if it is not there.
   
   

   pop3_uidl_format = %08Xu%08Xv
   pop3_client_workarounds = outlook-no-nuls oe-ns-eoh

   
   
   
8. Please use the below command to create a user. Here, we have used a test user.
   
   

   sudo useradd test

9. Create the mail directory for the test user.
   
   

   sudo mkdir /home/test/Maildir

10. Assign the Mail directory permission to the created user.
    
    

    sudo chown test:test /home/test/Maildir
    sudo chmod -R 700 /home/test/Maildir
    

    
    
    
11. Run below command to start dovecot service.
    
    

    # sudo service dovecot start

12. To Connect your email client to SMTP server, you will need to configure Postfix.
    
    
13. Open the file /etc/postfix/main.cf using vi editor.
    
    

    sud vi /etc/postfix/main.cf

14. Add the below lines.
    
    

    # authentication
     smtpd_sasl_security_options = noanonymous
     smtpd_sasl_auth_enable = yes 
     smtpd_sasl_type = dovecot
     smtpd_sasl_local_domain = $hostname
     broken_sasl_auth_clients = yes
     smtpd_sasl_path = private/auth

15. Restart the Postfix service.
    
    

    # sudo service postfix restart

16. You will need to allow the below ports in your firewall.
    
    

    110,143,465,587,993,995