Bulk email industry standards and best practices
Best practices to help bulk email you send to Yahoo email addresses get to your contacts.
SMTP error code table
Common SMTP error codes when sending messages to Yahoo Mail accounts, and why you would receive them.narrowed first column in table
Yahoo Outbound IP addresses
See the IP addresses that Yahoo Mail sends emails from.
DomainKeys Identified Mail and Yahoo Mail
Yahoo Mail uses DKIM to fight email forgery.
Error: All messages from x.x.x.x permanently deferred when sending email to Yahoo
Find out why this error happens and see our recommendations for preventing it in the future.
Yahoo Mail deliverability FAQs
Get the answers to commonly asked questions about email deliverability to Yahoo Mail accounts.
Yahoo DMARC policy
Learn why emails sent to Yahoo Mail accounts might be returned as a result of recent updates to Yahoo's DMARC policy.
4xx or 5xx SMTP error message notifications
Learn what causes SMTP errors and get tips for email administrators on how to troubleshoot them.
Yahoo Complaint Feedback Loop service FAQ
Get answers to the most common questions regarding the Yahoo Complaint Feedback Loop (CFL) service.
