At one point we had set-up a separate domain just for our outgoing NetSuite marketing emails.  It was a requirement at the time to send out mass emails from NetSuite.

Now, when I set-up a new marketing campaign it only gives me TWO choices for the domain setting in the Marketing Template.

Choice one: leave the domain blank
Result: The "manage email subscription" link at the bottom of our marketing emails will bring up a NetSuite error page.

Choice two: pick the special email domain (different than our WebStore domain)
Result: The "manage email subscription" link at the bottom of our marketing emails will bring up a generic bad URL error because is uses the "email domain" as the domain in the link and that domain has no website as it was just intended for email use.