{% call macros.panel("info", "Step 4 - expose Mailu to the world") %}

A mail server must be exposed to the world to receive emails, send emails, and let users access their mailboxes. Mailu has some flexibility in the way you expose it to the world.

Among Mailu services, the front server is the one accepting connections, be it directly from the outside world, through a reverse proxy or in any complex configuration that you might want to setup. It needs to listen on some IP addresses in order to expose its public services. You must at least setup an IPv4 or an IPv6 address if you wish to access Mailu.

Warning You must use specific addresses, please avoid generic all-interfaces addresses like 0.0.0.0 or ::. How to find these addresses.

The unbound resolver enables Mailu to do DNSsec verification, DNS root lookups and caching. This also helps the antispam service not to get blocked by the public or ISP DNS servers.

You server will be available under a main hostname but may expose multiple public hostnames. Every e-mail domain that points to this server must have one of the hostnames in its MX record. Hostnames must be comma-separated. If you're having trouble accessing your admin interface, make sure it is the first entry here (and possibly the same as your DOMAIN entry from earlier). Also make sure that the first entry in this list resolves to the IP address of your server, and that the reverse DNS entry for the IP address of your server resolves to this first entry in this list.

{% endcall %}