Finally a great tool using one of the public Windows Live SDKs has been released. Frameworkx have created a full Windows-based Management Console for Windows Live Custom Domains, through which you can perform the following tasks:
– Veirfy Service Status – Verify MX Configuration – Add New Users – Delete Users – Import Existing Users – Evict Existing Users – Import User List – Export User List – Centralized Multi-domain Management
I'd highly recommend giving the Custom Domains service a try if you haven't already, though I find the lack of POP3 support more than a minor annoyance. On a related note, if anybody has tested Custom Domains with Mail Desktop then I'd love to hear what happened, especially whether you were able to synch the account.
Windows Live Custom Domains Manager(Requires .Net Framework 2.0)