XFOR: How to Control Routing of Subdomains in Internet Mail Service Routing (217217)

SUMMARY

In the properties for the Internet Mail Service, there is an option to enable routing. For the Internet Mail Service to still properly receive mail for the local domain, that domain must be entered and marked as <inbound>. The result is that all subdomains of the higher-level domain are also accepted as inbound. Although you can specify that some subdomains be handled differently, this approach can become problematic in the case of a large number of subdomains.

MORE INFORMATION

Assume a domain of sample.microsoft.com with subdomains of dallas.sample.microsoft.com, seattle.sample.microsoft.com, and chicago.sample.microsoft.com. In this organization, mail for chicago.sample.microsoft.com is handled by a separate host. In the Internet Mail Service, the following entries are present:

sample.microsoft.com <inbound>
chicago.sample.microsoft.com <route to other host for this subdomain>

This Internet Mail Service server accepts sample.microsoft.com and all its subdomains as inbound, redirecting mail for chicago.sample.microsoft.com to the other host. This scheme works well if there are few subdomains to be rerouted in this manner, but becomes unwieldy if there are many subdomains to be rerouted. In this instance, prepending "#" creates an explicit route that ignores subdomains. For sample.microsoft.com, the table looks like:

#sample.microsoft.com <inbound>
dallas.sample.microsoft.com <inbound>
chicago.sample.microsoft.com <route to other host for this subdomain>

For this example, only two subdomains are accepted as inbound on this server: sample.microsoft.com and dallas.sample.microsoft.com. The chicago.sample.microsoft.com is rerouted to the other host, and seattle.sample.microsoft.com (and any other unlisted domain) is rerouted by whatever method is specified on the Connections tab for the Internet Mail Service.

NOTE: Subdomains of dallas.sample.microsoft.com (such as plano.dallas.sample.microsoft.com) are also accepted inbound implicitly; prepending with the "#" sign also forces this entry to be explicit if you want.

The example companies, organizations, products, people and events depicted herein are fictitious. No association with any real company, organization, product, person or event is intended or should be inferred.