This tutorial shows how to prepare a Debian 9 server (with Nginx, BIND, Dovecot) for the installation of ISPConfig 3.1, and how to install ISPConfig 3.1. ISPConfig 3 is a web hosting control panel that allows you to configure the following services through a web browser: Apache or nginx web server, Postfix mail server, Courier or Dovecot IMAP/POP3 server, MySQL, BIND or MyDNS nameserver, PureFTPd, SpamAssassin, ClamAV, and many more. This setup covers Nginx web server, BIND as DNS Server, and Dovecot as IMAP / POP3 server.
Read more at HowtoForge: https://www.howtoforge.com/tutorial/perfect-server-debian-9-nginx-bind-dovecot-ispconfig-3.1/