In reply to:
This email spam issue is an interesting one. Under what circumstances will Dreamhost terminate an accout for spamming? Does it have to be through the dreamhost smtp? Does the return address have to be marked as a dreamhost web hosted domain?
In other words, would it indemnify you from the spam rules by using a non-dreamhost mail server?
Not according to the way I read the Anti-Spam Policy and the information on the DreamHost Abuse Center.
From the Anti-Spam Policy:
In reply to:
Mailing Practices .....
3. Users are responsible for the practices of any affiliate program members they solicit the help of, as if they were hiring an outside advertising agency.
4. Users using either outside advertising companies or 3rd party mailing programs must abide by the same policies and practices as those using DreamHost's own bulk mailing list tools.
,,,
Disablement
1. DreamHost reserves the right to disable any account at any time should it feel there is a reasonable suspicion that it is being used in conjunction with the practice of spamming.
While there may some arguable ambiguity in some of this, the information in the DreamHost Abuse Center makes it pretty clear to me:
In reply to:
Common questions & misunderstandings
There are a number of frequently asked questions we receive about our anti-spam policies, some of which reflect common misunderstandings both about the spam problem and our policies in particular. They are as follows:
"What if I send the email from a non-DreamHost server?"
You are still required to comply with our policies if this mailing is being done in conjunction with our services in any way. That includes emails sent in promotion of a site or domain that we host (ie. you are pointing people toward your site via a link, hosting embedded email graphics on our servers, referring to a DreamHost-hosted email address, etc).
To me, that is pretty clear: If is is not provable confirmed opt-in, and in every other way compliant with DH's Anti Spam policy, and is *in any way* connectible to your DH hosted site, it could result in your account being terminated. And really, that makes perfect sense if they are serious about not being associated with spam operations. 
--rlparker