Setup Email server using docker instance of Poste.io Note: Steps in this article have been followed on Ubuntu 18.04 server machine. Setting up of email server is considered to be one of the most difficult tasks to do. There have been number of efforts to make this process easy and secure. Some of the notable projects are: tvial/docker-mailserver Mailu Poste.io By far the simplest server to setup that I found was Poste.