The new Gmail and Yahoo changes strongly emphasize email authentication, particularly DMARC alignment, for senders using branded domains. For those already following best practices, including correct SPF, DKIM, and DMARC setup, the changes should improve deliverability by filtering out unauthenticated email. However, senders lacking proper authentication or with misconfigured settings risk deliverability issues, such as emails being rejected or marked as spam. Google's requirements apply to senders sending over 5,000 messages a day. Domain owners must actively monitor DMARC reports, maintain a good sender reputation, and ensure all authentication records are correctly configured. A correct setup also involves using the appropriate 'from' domain and also ensuring DMARC is configured if using subdomains.