<p>Set-up the following DNS records at your domain registrar to define the required DNS reference alias mappings:</p> <pre><code>| Host | Type | Content | |---------|-------|-------------------| | @ | MX | 10 @ | | @ | A | public ip-address | | imap | CNAME | @ | | smtp | CNAME | @ | | webmail | CNAME | @ |</code></pre> <blockquote> <p><code>@</code> <code>MX</code> is an <a href="https://pressable.com/blog/2014/12/23/dns-record-types-explained/">DNS MX record</a> (alias) that refers - with priority <code>10</code> - to <code>@</code> as its target for MX requests (i.e. incoming e-mails go to '@', being the specific 'A' record, in-turn resolving to the ip-address in the next row).</p> <p><code>@</code> <code>A</code> is the domain root (e.g. example.org) <a href="https://pressable.com/blog/2014/12/23/dns-record-types-explained/">DNS A record</a> (alias) that refers to <code><public ip-address></code> (the external ip-address of the mailserver) as its target for A record requests (i.e. example.org requests go to 123.234.123.12).</p> <p><code>imap</code>-, <code>smtp</code>-, and <code>webmail</code> <code>CNAME</code> are subdomain (e.g. webmail.example.org) <a href="https://pressable.com/blog/2014/12/23/dns-record-types-explained/">DNS CNAME records</a> (aliases) that refer to <code>@</code>, being the specific 'A' record, in-turn resolving to an ip-address defined in the second row.</p> </blockquote> <!-- REFERENCES -->