Using Direct Links3273Using Direct LinksWhen you connect two domains in different GroupWise® systems through direct links (mappeddrive, UNC path, or TCP/IP connection), both systems remain external to each other, meaning thatthey must be administered separately. However, you can exchange information (domains, postoffice, users, resources, and distribution lists) so that the two systems look like one system to yourGroupWise users.The following sections provide information to help you connect two systems via direct links: Section 3.1, “Overview,” on page 27 Section 3.2, “Creating an External Domain,” on page 28 Section 3.3, “Linking to the External Domain,” on page 29 Section 3.4, “Checking the Link Status of the External Domain,” on page 30 Section 3.5, “Sending Messages Between Systems,” on page 30 Section 3.6, “Exchanging Information Between Systems,” on page 31 Section 3.7, “Message Flow Between External Domains,” on page 313.1 OverviewFor the purpose of the following discussion, GroupWise System 1 and GroupWise System 2represent two separate GroupWise systems.A direct link requires an MTA in GroupWise System 1 to have access via a mapped drive or UNCpath to a domain directory in GroupWise System 2, or to have a TCP/IP connection to a domain’sMTA in GroupWise System 2. Likewise, an MTA in GroupWise System 2 must have the same typeof access to GroupWise System 1.To create a direct link between GroupWise System 1 and GroupWise System 2, you would do thefollowing: In GroupWise System 1, define one domain from GroupWise System 2 as an external domainand then configure a direct link from a domain in GroupWise System 1 to the external domain.This allows GroupWise System 1 to deliver messages to GroupWise System 2. In GroupWise System 2, define one domain from GroupWise System 1 as an external domainand then configure a direct link from a domain in GroupWise System 2 to the external domain.This allows GroupWise System 2 to deliver messages to GroupWise System 1. After you’ve connected the two systems, users can send messages to the other system byentering the recipients’ full addresses (userID.post_office.domain or user@host). If desired,you can simplify addressing by exchanging information between systems, which causes userinformation to be displayed in the Address Book. The easiest way to exchange information is toenable the External System Synchronization feature in both systems. When enabled, thissynchronization constantly updates the Address Books in both systems so that local users canmore easily address messages to and access information about the users in the external system.If you don’t want to enable the External System Synchronization feature, you can manuallyexchange information. For information about External System Synchronization, see “External