The playbook can install and configure [email2matrix](https://github.com/devture/email2matrix) for you.
See the project's [documentation](https://github.com/devture/email2matrix/blob/master/docs/README.md) to learn what it does and why it might be useful to you.
It's not strictly necessary, but you may increase the chances that incoming emails reach your server by adding an `MX` record for `matrix.DOMAIN`, as described in the [Configuring DNS](configuring-dns.md) documentation page.
If you have `postfix` or some other email server software installed, you may need to manually remove it first (unless you need it, of course).
If you really need to run an email server on the Matrix machine for other purposes, it may be possible to run Email2Matrix on another port (with a configuration like `matrix_email2matrix_smtp_host_bind_port: "127.0.0.01:2525"`) and have your other email server relay messages there.
For details about using Email2Matrix alongside [Postfix](http://www.postfix.org/), see [here](https://github.com/devture/email2matrix/blob/master/docs/setup_with_postfix.md).
Before enabling Email2Matrix, you'd most likely wish to create a dedicated user (or more) that would be sending messages on the Matrix side.
Refer to [Registering users](registering-users.md) for ways to do that. A regular (non-admin) user works best.
### Creating a shared room
After creating a sender user, you should create one or more Matrix rooms that you share with that user.
It doesn't matter who creates and owns the rooms and who joins later (you or the sender user).
What matters is that both you and the sender user are part of the same room and that the sender user has enough privileges in the room to be able to send messages there.
Inviting additional people to the room is okay too.
Take note of each room's room id (different clients show the room id in a different place).
You'll need the room id when doing [Configuration](#configuration) below.
In order for the sender user created above to be able to send messages to the room, we'll need to obtain an access token for it. Refer to the documentation on [how to obtain an access token](obtaining-access-tokens.md).
You can also set `MatrixHomeserverUrl` to the container URL where your homeserver's Client-Server API lives by using the `{{ matrix_addons_homeserver_client_api_url }}` variable, instead of the public `https://matrix.DOMAIN` endpoint.