Book Image

Ubuntu Server Essentials

By : Abdelmonam Kouka
Book Image

Ubuntu Server Essentials

By: Abdelmonam Kouka

Overview of this book

Ubuntu is a Debian-based Linux operating system built on top of the Debian architecture. It is used to make operating systems for multiple platforms, including phones, desktops, TVs and mobiles. It has made some serious progress in the realms of efficiency and user friendliness. With evolving technology trends, demands on software have changed, with more and more skilled users. Over the past few years, services such as Facebook, Twitter, and push notifications on smartphones mean that users are used to being up to date with everything that happens all the time. With SignalR, the applications stay connected and will generate notifications when something happens either from the system or by other users. This provides new opportunities for the system administrators, to enter this new and exciting world of real-time application development. This is a concise and a cost-friendly guide, packed with up-to-date essentials on Ubuntu Server fundamentals. It will guide you through deploying and configuring Ubuntu servers in your office environments. You’ll start by installing Ubuntu Server, then move to the most useful aspect —the command-line interface inside it. You’ll extend your knowledge by learning how to administrate and configure Ubuntu Server. You will also see how to deploy services on Ubuntu Server and find out how to secure it. You’ll get to grips with the virtualization and cloud computing facilities provided by Ubuntu, and finally, you’ll gain some very useful tips.
Table of Contents (13 chapters)

Deploying an e-mail server


Along with the Web, e-mail is probably the service that most people think of when they think of the Internet. Like web servers, e-mail servers have traditionally been pretty tricky to set up, and there are many guides and books on this subject. However, you will find that e-mail servers are pretty easy to set up and use under Ubuntu.

Installing an e-mail server requires you to manage the sending and receiving of e-mails. These two notions are important because they implement two different protocols—SMTP to send, and POP or IMAP to receive the messages.

When a user sends an e-mail it is in fact never in direct contact with the recipient. The e-mail goes through at least two servers that are, in order, the sending server (SMTP), called the MTA (Mail Transfer Agent), which sends it to the receiver server (POP or IMAP), called MDA (Mail Delivery Agent), possibly transiting the e-mail via other SMTP servers as well. Then, the e-mail will wait on this last server until...