How can domain alignment errors affect Yahoo placement?

Domain alignment errors at Yahoo affect placement by weakening authentication signals. Alignment requires that the domain in your SPF or DKIM authentication matches (or is a subdomain of) your From header domain. Misalignment means authentication passes technically but does not fully validate your sending identity.

Yahoo checks alignment as part of DMARC validation. When SPF passes but the sending IP's authorized domain does not align with your From domain, and DKIM similarly misaligns, DMARC fails. This failure triggers the policy specified in your DMARC record, potentially causing rejection or quarantine.

Common alignment issues include using ESP shared infrastructure without custom authentication, sending from subdomains without proper DMARC inheritance, or misconfigured DKIM selectors. Fixing alignment requires coordinating your DNS records with your actual sending infrastructure to ensure everything matches.