What is the process for undoing identification of a senders email address as being spam?

You can send them to your "Blocked Addresses List".


Click on "Options" from your yahoo in-box in the upper right.


Click on "Block Addresses".


Enter the senders email address into the box that opens and click on "Add Block".

What is the process for undoing identification of a senders email address as being spam?
You mean you want to "unspam" someone that you spammed???


Look in the Bulk folder for the email that you spammed. Mark it as "Not Spam". And... look in the list of blocked addresses (Options %26gt; Block Addresses) for that address, select it, and click Remove Block.