How does Mail Utilities determine which global catalog to use?

SYMPTOMS

In a complex infrastructure, it is not clear which global catalog server(s) will be used by Exclaimer for its message categorization.

CAUSE

Various versions of Exclaimer have different strategies when it comes to locating a suitable global catalog server. This knowledge base article details these.

MORE INFORMATION

Exclaimer 2.22
GC://rootDSE queried for dnsHostName which was using in the construction of the query. This resulted in a fixed machine within the domain causing a server bind. This had no capability to failover if the dnsHostName returned from the rootDSE query failed.
Exclaimer 2.36
GC://rootDSE queries for dnsHostName which is then concatenated to form a server-less domain bind to permit a load-balancing effect. Under loaded conditions, the GC could be re-established to reduce the load on the busy catalog server, however due to an apparent bug in the way the rootDSE object is implemented, this never returned any other value that the first one.
Exclaimer 3.x
DcGetDcName is used to collect the DNS name of the appropriate server in the domain to query. Under loaded or error conditions, Exclaimer forces a rediscovery within the domain to reduce the load on this busy server.
Exclaimer 4.x
The same strategy is used for the 4.x version as is used in the 3.x versions.

APPLIES TO

• Exclaimer 2.x
• Exclaimer 3.x
• Exclaimer 4.x

Article ID: 20041120
Last Reviewed: 18th April 2005
Revision: 1.0