# Multiple domains configuration

## Separate account namespaces

Given two domains, example.org and example.com. foo@example.org and
foo@example.com are different and completely independent accounts.

All changes needed to make it work is to make sure all domains are specified in
the `$(local_domains)` macro in the main configuration file. Note that you need
to pick one domain as a "primary" for use in auto-generated messages.
```
$(primary_domain) = example.org
$(local_domains) = $(primary_domain) example.com
```

The base configuration is done. You can create accounts using
both domains in the name, send and receive messages and so on.  Do not forget
to configure corresponding SPF, DMARC and MTA-STS records as was
recommended in the [introduction tutorial](tutorials/setting-up.md).

## Single account namespace

You can configure maddy to only use local part of the email
as an account identifier instead of the complete email.

This needs two changes to default configuration:
```
storage.imapsql local_mailboxes {
    ...
    delivery_map email_localpart
    auth_normalize precis_casefold
}
```

This way, when authenticating as `foxcpp`, it will be mapped to
`foxcpp` storage account. E.g. you will need to run
`maddy imap-accts create foxcpp`, without the domain part.

If you have existing accounts, you will need to rename them.

Change to `auth_normalize` is necessary so that normalization function
will not attempt to parse authentication identity as a email.

When a email is received, `delivery_map email_localpart` will strip
the domain part before looking up the account. That is,
`foxcpp@example.org` will be become just `foxcpp`.

You also need to make `authorize_sender` check (used in `submission` endpoint)
accept non-email usernames:
```
authorize_sender {
  ...
  auth_normalize precis_casefold
  user_to_email regexp "(.*)" "$1@$(primary_domain)"
}
```
Note that is would work only if clients use only one domain as sender (`$(primary_domain)`).
If you want to allow sending from all domains, you need to remove `authorize_sender` check
altogether since it is not currently supported.

After that you can create accounts without specifying the domain part:
```
maddy imap-acct create foxcpp
maddy creds create foxcpp
```
And authenticate using "foxcpp" in email clients.

Messages for any foxcpp@* address with a domain in `$(local_domains)`
will be delivered to that mailbox.