``DOMAIN`` is the main mail domain. Aka, server identification for outgoing mail. DMARC reports point to ``POSTMASTER`` @ ``DOMAIN``.
These are really the only things it is used for. You don't need a cert for ``DOMAIN``, as it is a mail domain only and not used as host in any sense.
However, it is usual that ``DOMAIN`` gets setup as one of the many mail domains. None of the mail domains ever need a certificate.
TLS certificates work on host connection level only.
``HOSTNAMES`` however, can be used to connect to the server. All host names supplied in this variable will need a certificate. When ``TLS_FLAVOR=letsencrypt`` is set,
a certificate is requested automatically for all those domains.
So when you have something like this:
..code-block:: bash
DOMAIN=example.com
POSTMASTER=me
HOSTNAMES=mail.example.com,mail.foo.com,bar.com
TLS_FLAVOR=letsencrypt
- You'll end up with a DMARC address to ``me@example.com``.
- Server identifies itself as the SMTP server of ``@example.com`` when sending mail. Make sure your reverse DNS hostname is part of that domain!
- Your server will have certificates for the 3 hostnames. You will need to create ``A`` and ``AAAA`` records for those names,
pointing to the IP addresses of your server.
- The admin interface generates ``MX`` and ``SPF`` examples which point to the first entry of ``HOSTNAMES`` but these are only examples.
You can modify them to use any other ``HOSTNAMES`` entry.
You're mail service will be reachable for IMAP, POP3, SMTP and Webmail at the addresses:
- mail.example.com
- mail.foo.com
- bar.com
..note::
In this case ``example.com`` is not reachable as a host and will not have a certificate.
It can be used as a mail domain if MX is setup to point to one of the ``HOSTNAMES``. However, it is possible to include ``example.com`` in ``HOSTNAMES``.
*Issue reference:*`742`_, `747`_.
How does Mailu scale up?
````````````````````````
@ -123,6 +168,16 @@ For **service** HA, please see: `How does Mailu scale up?`_
Next, you have to enable External user support from Nextcloud Apps interface
In the end you need to configure additional user backends in Nextcloud’s configuration config/config.php using the following syntax:
..code-block:: bash
<?php
'user_backends' => array(
array(
'class' => 'OC_User_IMAP',
'arguments' => array(
'{imap.example.com:993/imap/ssl}', 'example.com'
),
),
),
If a domain name (e.g. example.com) is specified, then this makes sure that only users from this domain will be allowed to login.
After successfull login the domain part will be striped and the rest used as username in NextCloud. e.g. 'username@example.com' will be 'username' in NextCloud.
Ionut Filip
6 years ago
