My father in law have told me that he can't send me mail from his local internet cafe in Bali, Indonesia.
He receives some 5xx error code, and that the RBL doesn't like his IP address.
He uses yahoo web mail, and at first I thought that it couldn't be possible that his message bounces on the basis of yahoo's IP. But after reading this list, it seems that this is common practice?
Or could it be that the mail is blocked based on the internet cafe's/providers IP adress(es)? This could only mean that a check is done on the 'X-originating-IP' header.
I am sorry that I can't provide you with any IP addresses at tihis time. I would just like to check what is the most probable reason for the block.