This issue is caused by Earthlink and/or ATT, AOL and various others, who routinely and arbitrarily count emails as spam --- SOLELY because a user of theirs marks an email as "spam." This is their way to "manage spam."
We have tried to get ATT, AOL and other services to "unblock" our address for almost 3 years. We have submitted, re-submitted and contacted all of these services, and also had our top sysadmin directly try to resolve the issue. Either they do not understand, or do not care, that we and our users, along with tens of millions of others are affected in this way.
So long as 1) these services provide their users with a big "Report As Spam?" button, and 2) if they get a few, or even ANY emails reported in this manner, they will block an ISP, you will have this problem. We are not causing it, and cannot resolve it.
Believe me, I wish their were an easy solution, but there is not any available from such providers. As long as there is email, and as long as these companies use arbitrary and ruthless methods such as this, blocked emails are going to occur.
My suggestion is that you open a Gmail account and use that for your TBN and similar affected providers. Gmail at least has intelligent people behind it, with very sophisticated spam fighting algorithms that do not destroy legitimate email. They can and do distinguish between true spammers, and large sites like TBN that generate significant legitimate emails as part of doing business.
Glad you have a handle on it now. Let us know the results. :thumbsup: