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.

Email sent to Yahoo Mail addresses is rejected

Learn about possible SMTP errors that happen when your email is rejected by Yahoo Mail.

Complaint Feedback Loop program

Learn how to subscribe or unsubscribe from CFL reports, and how Yahoo is helping bulk senders understand and minimize complaint rates.

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.

Yahoo Mail deliverability FAQs

Get the answers to commonly asked questions about email deliverability to Yahoo Mail accounts.

Yahoo Complaint Feedback Loop service FAQ

Get answers to the most common questions regarding the Yahoo Complaint Feedback Loop (CFL) service.

Help for Postmaster sending issues

Get the resources to resolve issues sending email to Yahoo Mail accounts.

4xx SMTP error codes

Learn what each 4xx SMTP error code means, and how you can prevent them from happening in the future.