ultimatebizsource.biz claims to be an opt-in list with 55,000 subscribers. It's currently listed on [WS] and [JP] but not my personal list.
I know, the name alone sounds like your typical spammer domain, but is it? Today the owner of getyoursiteongoogle.info mailed me, since I had blacklisted their domain.
Turns out the evidence was a mailing from ultimatebizsource.biz which was listed on WS and JP. Since the recipient was a third party from the Prolocation feed, I could not easily verify if it was indeed unsolicited, but I checked what I could check quickly.
To my surprize the outgoing mailserver's IP is not listed on any of the RBLs and neither are the name servers or the resolved name.
There is only 1 NANAS sighting for this almost one year old domain. That posting is an automated one, and probably related to an ahbl.org listing mentioned in the SA-tags added to the evidence mail. I can find no listing for them at ahbl.org now.
A web search for the domain name returns a single hit: http://www.google.com/search?q=ultimatebizsource.biz+spam
That looks too little for 55,000 mails per day for one year.
Joe