MAKEHOSTEDDOMAINS(8)

NAME
makehosteddomains - Build a database of hosted domains

SYNOPSIS
makehosteddomains

DESCRIPTION

makehosteddomains rebuilds the contents of the @sysconfdir@/hosteddomains.dat database from the contents of @sysconfdir@/hosteddomains. This can be either a file or a directory. If it's a directory, the contents of all the files in this directory are simply concatenated. The makehosteddomains script must be run in order for any changes to @sysconfdir@/hosteddomains to take effect.

The function of @sysconfdir@/hosteddomains is very similar to the one of @sysconfdir@/locals. Both configuration files specify a list of domains that are considered to be local domains - domains whose mailboxes are stored locally.

The difference is that domains listed in @sysconfdir@/locals are removed from addresses before their mailbox is looked up. For example, if the domain "example.com" is listed in @sysconfdir@/locals, then the address <user@example.com> is delivered to a local mailbox named "user". If this domain is listed, instead, in @sysconfdir@/hosteddomains, then the address <user@example.com> is delivered to a local mailbox named "user@example.com". Usually you would use @sysconfdir@/locals to specify domains that correspond to your local system accounts, that are looked up in your system's password database. The @sysconfdir@/hosteddomains file is usually used when you have database-based virtual domains, that are maintained via an LDAP or a MySQL server. Courier's LDAP and MySQL authentication modules will use the full E-mail address to query the LDAP or MySQL server for the location of the local mailbox that correspond to the E-mail address. Courier's authuserdb authentication module can also use full E-mail addresses.

  CONTENTS OF HOSTEDDOMAINS

The file @sysconfdir@/hosteddomains simply contains a list of domains, one per line, for example:

domain.com
example.org

Each domain can optionally be followed by a single tab character, in order to specify an alias for a domain, for example:

domain.com
mail.domain.com<TAB>domain.com
example.com<TAB>domain.com

First, we list the domain "domain.com" as a hosted domain. Then, we also list the domain "mail.domain.com", which is an alias for domain.com. Courier will take any address of the form <address@mail.domain.com>, rewrite it as <address@domain.com>, and attempt to deliver the mail to a local mailbox for that name. The third entry does the same for "example.com"; mail addressed to <address@example.com> is delivered to the local mailbox <address@domain.com>.

  ALIAS@HOSTEDDOMAIN

This is a special local mail delivery rule for hosteddomain-listed domains. This rule allows Courier accept mail to any address@hosteddomain, where "hosteddomain" is a domain listed in the hosteddomains file, but there is no corresponding account for address@hosteddomain. To provide delivery instructions for any non-existing address in a hosteddomain-listed domain:

1) Create the local address alias@hosteddomain. For example, if the hosteddomains file contains "example.com", create the local account alias@example.com. This should be a normal account, with its own home directory, userid and groupid.

2) Create $HOME/.courier-default file in this account, containing the delivery instructions. See the dot-courier(5) manual page for avaiable delivery instructions.

NOTE that alias@example.com must be a real account, not a mail alias. If you want to forward alias@example.com to another address, put forwarding instructions in the .courier-default file. However, alias@example.com can be a clone of another account (with the same home directory, userid, and groupid).

  ``WILDCARD DNS''

Wildcard DNS is supported for hosteddomains by placing a single period character before the domain name. For example, the hosted domain entry ``.domain.com'' will cause Courier to accept mail for ``anything.domain.com''.

Courier will accept mail for <address@any.thing.domain.com> and attempt to deliver it to the local mailbox <address@any.thing.domain.com>, and if that fails then attempt to deliver the mail to the local mailbox <address@.thing.domain.com>, then finally <address@.domain.com>

    Note:

    There is a period after the '@' character. If you want all mail for ``any.thing.domain.com'' to be delivered as though it were sent to ``domain.com'', you should define an alias for the domain, for example:

    domain.com
    .domain.com<TAB>domain.com

SEE ALSO

esmtpd(8).