PMDF System Manager's Guide
PMDF-REF-6.0

The X.400-gateway-domain is defined during the PMDF-X400 configuration process. Then when PMDF encounters an address containing X.400-gateway-domain, it will direct the message to PMDF-X400. X.400-gateway-domain may be any legal Internet-style domain name. A typical choice would be something like X400 followed by the Internet domain assigned to your organization. If your organization has not been assigned a domain name, you can use whatever name you choose. Remember that the name chosen for the X.400-gateway-domain is normally one that users will need to use when they want to send through the gateway to X.400 recipients.

Examples of typical X.400-gateway-domain names are shown below:

	X400.ACME.COM	under the domain ACME.COM
	X400	no domain available --- just a simple name

When PMDF-X400 is configured for connections to more than one remote X.400 MTA, there is still only one X.400-gateway-domain The appropriate remote MTA is determined solely by the contents of the X.400-OR-name part of each address. PMDF-X400 does not currently support more than one X.400-gateway-domain.

If the PMDF-X400 gateway is intended for use by mail systems on hosts other than the local PMDF/PMDF-X400 system or cluster, then some mechanism must be used in order to get the remote mail system to route messages to the local PMDF/PMDF-X400 host when X.400-gateway-domain is used as part of the recipient address. In the case of TCP/IP hosts using a domain name server, this is best implemented using the MX record facility of the Domain Name System.

An MX record for X.400-gateway-domain should be added to the name server database. The MX record should point to the TCP/IP domain name for the system running the PMDF/PMDF-X400 gateway.

In a TCP/IP environment which does not use a domain name server, then X.400-gateway-domain can be added to the host name definition files on remote hosts. X.400-gateway-domain should be entered as a new host which has the same IP address as the system running the PMDF/PMDF-X400 gateway.

Note:

Do not put the X.400-gateway-domain name into the remote hosts files as an alias. It must appear as a separate host entry which happens to have the same IP address as the system running the PMDF/PMDF-X400 gateway. Many mailers attempt to resolve alias or CNAME entries by substituting the alias name with the canonical host name, which will lose the X.400-gateway-domain name entirely. For the same reason you should not use CNAME records if adding X.400-gateway-domain to a DNS server. Make sure that you use MX records instead. If MX records won't suffice for some reason, then A records can usually be used.