I would use our web services.
Specifically: svcDomainAdmin.GetAllDomains, svcUserAdmin.GetUsers and svcAliasAdmin.GetAliases.
This ties in to your other question, as well. You wouldn't need to worry about the .xml format.
For more information, take a look at these:
http://www.smartertools.com/portal/KB/a60/intro-to-web-services.aspx
http://www.smartertools.com/portal/KB/a83/using-smartermail-web-services.aspx
http://www.smartertools.com/portal/KB/a18/how-to-calling-web-services-from-microsoft-net.aspx
James LanceSenior Developer / Analyst
SmarterTools Inc.
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