White list - internet question

I don't have email through my internet provider, for reasons too complicated to elaborate, but ending with it being less expensive for me. I presently only use yahoo for email service.

I've gotten notice from some friends that their emails to me have bounced.
(My yahoo account is set for spam to go to Bulk Mail.) I've written to yahoo through their help page, but gotten no reponse.
At least one of these friends is listed in my YAHOO ADDRESSES. Is this the White list that I saw Timber mention on another thread?

I've also had some reports (say, on spammers) not come back with tickets from A2k, and Jespah is trying to trouble shoot that from the a2k end. It may also be a problem on my end, resulting in the tickets bouncing. Jespah mentioned that I should have @able2know.com on my White list, thus the question. The various a2k addresses aren't presently on my YAHOO ADDRESS list, and I'll add them. Just doublechecking that's the list you're talking about.