Unblock or change spam settings
Spam mails cancel
If u dont want spam mails
Go to options link on the yahoo mail page and then select mail options
Then under the spam section select 'delete spam mails' as immidately
Done no more spam mails for u
To see spam follow the same procedure and under the spam section select once in a month option
Blocking ids
To block a person from sending u a mail block his/her id
To do so go to options in the yahoomail page and then click on mail options
Under the spam tab and under the block adress option type the id u want to block and click on add
Then ciick on save and return back to ur mail page
To unblock a person from sending u a mail block his/her id
To do so go to options in the yahoomail page and then click on mail options
Under the spam tab and under the block adress option select the id u want to unblock and click on remove
Then clcik on save and return back to ur mail page

I'm having the same issue with a client. I created a brand new Yahoo account and still e-mail from the account which I've verified is on no outstanding spam lists (we even in desperation changed the domain name they send from and the actual IP address of the mail server and still the e-mails go to Bulk). Even innocuous messages like "Test 1.".

We have checked the web site and mail servers both domain names and IP addresses against various black lists and have found nothing. We are not blacklisted yet basically Yahoo is blacklisting email from our domain to users of Yahoo mail.

This is outrageous but we have no idea what to do about it.