Need help to setup postfix mail server with dovecot,roundcube

hi

need help to setup postfix mail server with dovecot and roundcube as realtime mailserver step by step using commandline interface

what i have

  1. one pc installed opensuse LEAP 42.2 with postfix , dovecot
  2. port 25, 110, 587, 465, 995, 993, mapped to local pc ip 192.168.1.7
  3. local pc ip is 192.168.1.7/255.255.255.0
  4. domain name re88.in bind to ipaddress 123.123.123.7 in reverse and forward zone by my isp.
  5. my localhost name is rbsingh and local domain name is suse.local so fqdn is rbsingh.suse.local
  6. local firewall is off

after configure my email address looks like yoyo@re88.in and able to send and rec. mails from windows outlook express, web client roundcube

please help.
thanks in advance
Doonali