<p>Besides providing a mailserver this guide includes some additional functional elements to make it a more complete operational system that is usable in daily life, whilst at the same time making it easier to manage. It defines four functional subsystems to this end:</p> <ul> <li>A <a href="/introduction/system-overview/?%3F%3FMailserver=1">Mailserver</a> core to send/receive (Postfix), store (Dovecot), scan (AMaViS), and filter (Sieve) e-mail, as well as manage user/domain account data (MariaDB).</li> <li>A <a href="/introduction/system-overview/?%3F%3FCerts=1">Certs</a> server to fetch, maintain, and serve SSL certificates (Dehydrated).</li> <li>A <a href="/introduction/system-overview/?%3F%3FWebmail=1">Webmail</a> website to provide users with a webinterface to access their e-mail (Rainloop),</li> <li>A reverse <a href="/introduction/system-overview/?%3F%3FProxy-server=1">Proxyserver</a> to centrally route https trafic to the webmail site and possibly other sites with a single point of maintenance.</li> </ul> <p>These functional subsystems are best isolated to separate concerns (e.g. rebooting a specific one - say 'webmail' - will not take others - such as 'mailserver' - offline with it). Additionally, virtualization can provide management flexibility (e.g. scalability, snapshots and easy backups). One way to do both is <a href="https://linuxcontainers.org/">containerization</a>.</p> <p><img src="https://media.discordapp.net/attachments/404696756840824832/406218268656009217/unknown.png" alt="System overview" /> <!-- !!! REPLACE IMAGE BY A CORRECT(UP-2-DATE)/MORE-CLEAR VERSION --></p> <!-- REFERENCES -->