Yahoo’s primary objective is to deliver messages that consumers genuinely want to receive while filtering out unwanted ones. The most effective way to guarantee delivery is by sending timely and relevant emails to an active and engaged audience.
Follow these recommended practices and tips to maximize the reach of your mailings.
For additional sender best practices, refer to the Messaging Anti-Abuse Working Group’s Senders Best Communications Practices Version 3.0.
- Send Emails that Customers Want
- Confirm that you’re exclusively sending mail to users who have explicitly requested it.
- Respect the frequency that aligns with the list’s original intent. Avoid suddenly switching from weekly or monthly mailings to daily ones for subscribers.
- Refrain from purchasing mailing lists or automatically subscribing users with pre-checked opt-in checkboxes on your website.
Ensuring Authentication: SPF, DKIM, and DMARC
Yahoo strongly recommends senders to implement DMARC policies for each domain used to send mail. DMARC, or Domain-based Message Authentication, Reporting & Conformance, enables a sender to indicate that their messages are secured by DKIM and/or SPF. It also instructs the receiver on what action to take if neither authentication method passes.
- Authenticate Every Email with DKIM
- DKIM (Domain Keys Identified Mail) generates a signature of the message’s content, allowing Yahoo to link the email with the sender and verify that the content hasn’t been altered during transmission.
- Publish Valid SPF Records
- SPF (Sender Policy Framework) records enable a sender to specify the list of IPs permitted to send mail for a particular domain. This helps Yahoo reject messages originating from IPs not listed in the domain’s SPF record.
Adhering to these recommendations will establish a consistent reputation for senders’ domains, regardless of the IP from which the mail is sent.
Organize Email Categories by IP or DKIM Domain
Avoid sending bulk or marketing emails from the same IPs or DKIM domains used for user communication, transactional messages, alerts, and the like. Each IP and DKIM domain carries its own reputation, which directly impacts email delivery. Sending unsolicited commercial emails can have adverse effects on your reputation. By segregating your emails based on their function, you enhance the chances of optimal delivery.
Implement OPT-IN Verification for Subscriptions
When users subscribe to your mailing list, initiate an email asking them to confirm their opt-in by clicking. This not only enhances user experience (preventing accidental or malicious sign-ups) but also ensures your list is free from uninterested parties, fake email addresses, and most automated bots.
Clearly Set Recipient Expectations for Subscribers
Be transparent about what mail users should expect, including frequency, content, and appearance, when they subscribe.
Facilitate Easy Unsubscribing
Support the One-Click Unsubscribe method, which enables a seamless one-click action for the List-Unsubscribe email header field. Refer to RFC 8058 for detailed instructions. Ensure the unsubscribe process is evident and easily accessible, without requiring users to log in. Additionally, process unsubscribe requests promptly.
Remove Inactive and Unresponsive Recipients
Sending emails to recipients who don’t engage or mark them as spam can adversely affect your delivery metrics and reputation. Keep an eye on both hard and soft bounces, as well as recipients who show little to no activity. Employ double opt-in or confirm opt-in methods to minimize invalid recipients, and promptly remove them from your list. Consider sending reconfirmation emails to inactive subscribers periodically.
Leverage Complaint Feedback Loop (CFL)
After implementing DKIM signatures, our CFL program assists in monitoring and managing your spam complaint rates. When users click “report spam,” you’ll receive a copy of the complaint. An active CFL is crucial for all DKIM domains to ensure prompt processing of complaints. Use the CFL to maintain a clean mailing list, and explore additional third-party tools available for CFL management.
Publish Reverse DNS (PTR) Records
Ensure that all your sending IPs have valid, specific, and descriptive reverse DNS (PTR) records. These records should reflect your domain name in a meaningful way. Avoid using a reverse DNS that resembles a dynamically-assigned IP, and instead, opt for one that signifies a static mail server.
Secure Your Mail Servers
Ensure the security of your mail servers by keeping them updated with the latest security patches to prevent unauthorized or anonymous usage. Filter user-generated content before transmission to thwart spammers from exploiting your resources. Be cautious about the potential risk of spammers attempting to send mail from your systems if they operate as “open proxies” or “open relays.”
Protect Against BGP Hijacking
Safeguard your IP space by adding routes for all the IP ranges you own. This precaution helps reduce vulnerability to BGP hijacking, which could enable hackers to send mail that falsely appears to originate from your IP space.
Manage Outbound Email Flow
Exercise control over the flow of your outbound emails:
- Implement limits on messages sent per connection to comply with Yahoo’s acceptance policy.
- If a connection is terminated without an error code, consider reestablishing the connection promptly.
- You may open concurrent connections from the same server for efficient message transmission. While specific guidelines are not provided, please use resources judiciously to ensure fairness to all users.
Compliance with CAN-SPAM Act and RFCs
Regardless of your location, adhere to the requirements outlined by the CAN-SPAM Act:
- The act sets standards for commercial messages, empowers recipients to opt out of further emails, and enforces penalties for violations.
- Avoid using false or misleading header information or deceptive subject lines to conceal, falsify, or misrepresent the sender or origin of the email.
- Ensure all emails comply with RFC 5321 and RFC 5322 standards.