How to Set Up a YAHOO FBL
Here is a link to their web-page for contacting YAHOO/AOL: https://senders.yahooinc.com/contact/
The attached document is a PDF describing how to set up an FBL for yahoo/AOL when working with DMS.
Please download and view the PDF.
If you have issues aftewards, contact yahoo customer care: https://io.help.yahoo.com/contact/index?page=home