<ol> <li> <p>Determine the hostname that is assigned to your <em>external</em> IP address to uncover the FQDN that is required during the installation wizard postfix (step 2.3):</p> <pre><code class="language-shell">getent hosts <IP ADDRESS></code></pre> </li> <li> <p>Install the SIMPLE MAIL TRANSFER PROTOCOL (SMTP) server <!-- Why each program? -->:</p> <ol> <li> <p>Start the (interactive) installer:</p> <pre><code class="language-shell">apt install -y postfix postfix-mysql</code></pre> </li> <li> <p>Choose <code>Internet Site</code>and click <code><OK></code>: <img src="https://user-images.githubusercontent.com/6719775/36641729-2bf19848-1a35-11e8-914b-6789f9c68d23.png" alt="image" /></p> </li> <li> <p>Fill in the FQDN (see step 1) of your registered domain per instruction and press <code><OK></code>: <img src="https://user-images.githubusercontent.com/6719775/36641754-8b4016a8-1a35-11e8-8271-60b4b958b336.png" alt="image" /></p> </li> </ol> </li> <li> <p>Install all remaining packages (non-interactively!) <!-- !!! Explain why each program? -->:</p> <pre><code class="language-shell"># Install OPENSSL to enable communication without eavesdropping apt install -y openssl # Install the DATABASE server apt install -y mariadb-server # Install the mail delivery server with LOCAL MAIL TRANSFER PROTOCOL (LMTP), INTERNET MESSAGE ACCESS PROTOCOL (IMAP), MAIL FILTERING, and MySQL DATABASE back-end support apt install -y dovecot-core dovecot-lmtpd dovecot-imapd dovecot-sieve dovecot-managesieved dovecot-mysql</code></pre> <blockquote> <blockquote> <blockquote> <blockquote> <blockquote> <p>For POP3 support also install <code>dovecot-pop3d</code>.</p> </blockquote> </blockquote> </blockquote> </blockquote> </blockquote> </li> </ol> <!-- REFERENCES -->