Summary
Yahoo open rates are declining due to various factors, including evolving algorithms, sender reputation issues, stricter spam filters, and potential server problems. TSS04 and TSS05 errors relate to spam filtering or security measures. Addressing these issues involves maintaining a good sender reputation through consistent engagement, proper authentication, list hygiene, monitoring feedback loops, and following Yahoo's guidelines. Staying informed about algorithm changes, continuously monitoring blocklists, utilizing the Yahoo feedback loop, and ensuring proper Reverse DNS configuration are crucial for improving deliverability.
Key findings
- Evolving Algorithms: Yahoo's continuously changing algorithms impact open rates, requiring constant adaptation.
- Sender Reputation Matters: Sender reputation, relevant content, and proper list management significantly affect deliverability.
- Stricter Spam Filters: Yahoo's stricter spam filtering rules and security measures can flag emails as suspicious, leading to TSS04 and TSS05 errors.
- Technical Compliance: Compliance with Yahoo's technical, list management, and content guidelines for bulk senders is crucial.
- Server Issues Impact: Temporary server issues on Yahoo's end can lead to deliverability problems.
- Feedback Loop Utility: Yahoo's feedback loop is essential for understanding how users perceive emails and identifying deliverability issues.
- Blocklist Monitoring Necessity: Continuous monitoring of blocklists is crucial for identifying and resolving listing issues affecting deliverability.
- Reverse DNS Importance: Properly configured Reverse DNS entries for mail servers are necessary to verify legitimacy and prevent emails from being marked as spam.
Key considerations
- Maintain Sender Reputation: Ensure consistent engagement, relevant content, and proper authentication (SPF, DKIM, DMARC) to maintain a positive sender reputation.
- Monitor and Adapt: Continuously monitor email performance, stay informed about algorithm changes, and adapt email practices accordingly.
- Address Spam Filters: Review email content to avoid triggering spam filters, and investigate/resolve issues that cause TSS04/TSS05 errors.
- Utilize Feedback Loop: Actively monitor and analyze data from Yahoo's feedback loop for actionable insights.
- Monitor Blocklists: Proactively monitor blocklists and take immediate action to resolve any listings.
- Comply with Guidelines: Adhere to Yahoo's bulk sender guidelines for technical requirements, list management, and content.
- Implement Reverse DNS: Configure Reverse DNS records for mail servers to improve deliverability and legitimacy.
What email marketers say
9 marketer opinions
Yahoo open rates have been dropping due to a combination of factors including changes to Yahoo's algorithms, sender reputation issues, stricter spam filtering, and potential temporary server issues. TSS04 and TSS05 errors indicate issues with spam filtering and security measures, possibly triggered by content or sender reputation.
Key opinions
- Algorithm Changes: Yahoo's algorithms are constantly evolving, leading to fluctuations in open rates. These changes are often opaque, requiring senders to adapt their email practices.
- Sender Reputation: Poor sender reputation, irrelevant content, and inadequate list hygiene negatively impact open rates. Maintaining a good sender reputation requires consistent engagement and proper authentication (SPF, DKIM, DMARC).
- Spam Filtering: Stricter spam filtering rules and security measures implemented by Yahoo can result in emails being flagged as suspicious and blocked, resulting in TSS04 and TSS05 errors.
- Server Issues: Temporary server overloads or maintenance on Yahoo's end can lead to temporary errors affecting email delivery.
- Global Impact: The decrease in open rates is observed across multiple senders and ESPs, indicating a widespread issue rather than isolated incidents.
Key considerations
- Monitor Performance: Continuously monitor Yahoo open rates and bounce rates to identify potential deliverability issues.
- Improve Reputation: Focus on improving sender reputation through consistent engagement, relevant content, and proper email authentication.
- Address Errors: Investigate and address TSS04 and TSS05 errors by reviewing email content, sender reputation, and authentication settings.
- Adapt to Changes: Stay informed about changes to Yahoo's email policies and algorithms and adapt email practices accordingly.
- Consider ESP Impact: Note that the impact of Yahoo's changes may vary across different ESPs. Clients using specific ESPs might experience more significant drops in open rates than others.
Marketer view
Email marketer from Email Geeks says it's now hundreds of dedicated senders on different ranges and junking is no longer the end of it - now it's blocking with TSS05 and TSS04.
2 Mar 2025 - Email Geeks
Marketer view
Email marketer from Email Geeks shares they are seeing a global drop in opens and tested inboxing across multiple platforms in a dozen of senders who are unrelated. Also mentions a spike in TSS05 on shared spaces, but not on dedicated IPs and has had confirmation from another ESP they're seeing a global dip in opens and inboxing, and a spike of TSSs on their senders.
19 Feb 2022 - Email Geeks
What the experts say
2 expert opinions
Addressing Yahoo open rate drops and resolving TSS04/TSS05 errors requires proactive monitoring and engagement with Yahoo's feedback mechanisms. Utilizing the feedback loop helps understand user perceptions and identify areas for improvement, while continuous monitoring of blocklists ensures quick identification and resolution of listing issues that impact deliverability.
Key opinions
- Feedback Loop Importance: Yahoo's feedback loop provides valuable insights into how users are marking emails, enabling senders to understand deliverability issues.
- Blocklist Impact: Being listed on blocklists significantly affects email deliverability to Yahoo.
Key considerations
- Implement Feedback Loop Monitoring: Actively monitor and analyze data from Yahoo's feedback loop to identify patterns and areas for improvement in sending practices.
- Proactive Blocklist Monitoring: Continuously monitor blocklists to promptly identify and address any listings that may affect email deliverability.
Expert view
Expert from Spamresource.com responds that continuously monitoring blocklists is essential. Being listed on a blocklist can significantly impact deliverability to Yahoo, and proactive monitoring allows for quick identification and resolution of any listing issues.
13 Oct 2021 - Spamresource.com
Expert view
Expert from Word to the Wise explains that utilizing Yahoo's feedback loop is crucial for identifying and addressing deliverability issues. Monitoring the feedback loop allows senders to understand how Yahoo's users are marking their messages, helping them to improve their sending practices.
27 Aug 2023 - Word to the Wise
What the documentation says
4 technical articles
Yahoo's email deliverability is affected by various factors outlined in documentation from Yahoo, RFC Editor, Microsoft and cPanel. Yahoo has specific guidelines for bulk senders focusing on technical, list management, and content requirements. TSS errors generally indicate temporary system or security issues on the receiving server's end. Specifically, TSS0004 relates to spam filtering from Hotmail/Outlook. Reverse DNS entries are crucial for verifying the legitimacy of mail servers and preventing emails from being marked as spam.
Key findings
- Yahoo Guidelines: Yahoo has specific guidelines for bulk senders concerning technical aspects, list management, and content.
- TSS Errors: TSS errors typically indicate temporary system or security issues on the recipient's mail server.
- TSS0004: TSS0004 is related to spam filtering triggered by Hotmail/Outlook systems, often due to email content.
- Reverse DNS: Reverse DNS entries are essential for verifying mail server legitimacy and preventing emails from being marked as spam.
Key considerations
- Follow Yahoo Guidelines: Ensure compliance with Yahoo's bulk sender guidelines to improve deliverability.
- Address TSS Errors: Investigate and resolve underlying issues causing TSS errors, such as server problems or security restrictions.
- Review Content: Examine email content to avoid triggering spam filters that result in TSS0004 errors.
- Configure Reverse DNS: Properly configure Reverse DNS entries for mail servers to establish legitimacy and improve deliverability.
Technical article
Documentation from cPanel explains Reverse DNS entries for mail servers are a crucial part of verifying that the mailserver is legitimate and not sending spam - it is also known as a PTR record. This can affect deliverability and cause emails to not get through.
17 May 2022 - cPanel
Technical article
Documentation from Microsoft says the error code TSS0004 relates to spam filtering that is triggered by the Hotmail/Outlook mail systems. Often relating to the content of the email and its likely to be marked as Spam
22 Oct 2023 - Microsoft
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