Yahoo has changed its DMARC policy for his domains. Yahoo prohibits third party email senders from using a @yahoo.com (and other yahoo domains such as yahoo.co.uk, etc.). All such messages sent from a Yahoo address outside the Yahoo infrastructure (via an email marketing platform) will be rejected by recipients' inboxes and will not be delivered.
Yahoo has changed its DMARC policy to ‘p=reject’. Any messages without a proper Domain Keys Identified Mail (DKIM) signature or Sender Policy Framework (SPF) alignment will be rejected and will generate a soft bounce. This action has been taken by Yahoo to effectively combat spam and phishing.
Gmail and AOL adopted similar policies. It is advisable to all users not to use your personal address of public domains as a sender. We recommend using your own domain in your sender. Following which you will enjoy better delivery to the end users.