In reply to:
retain the email acct structure
I don't think this is going to be possible. DreamHost has an unusual email system where each email address must be unique across the whole system. Your "username" becomes m1234567 (a unique seven-digit number), and then the email address you want is an alias of that. You will be able to choose your own password.
As far as I am aware, you must set each address up manually. You need to use the m1234567 username when configuring external mail clients (like Outlook, Thunderbird, etc.), and also with any webmail package that is not the default (Squirrel Mail).
This particular situation is not one of DreamHost's strong points, and it remains high on the list as one of the things customers would like to see changed.
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Simon Jessey | Keystone Websites
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