I agree, some kind of API exposing the functionality of the panel would be great and I am sure many people would find it useful. It wouldn't need to expose all the functionality of the panel, just the areas that people have expressed interest in, such as the automated creation of mailboxes/email addresses, users and sub-domains etc. Of-course, security would be a concern, but I am sure the bright folks at DreamHost are up to that challenge. Given the recent overhaul of the panel, now would seem to be the perfect time to implement something along these lines.
It is possible that this suggestion already exists in the DreamHost suggestion system, I haven't had a good look yet to see if this is the case. There are so many outstanding suggestions now that it is sometimes difficult to see exactly what is already in there, I think it needs a good clean-out.
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