Summary
Yahoo TSS09 errors indicate a severe deliverability issue resulting in permanent message deferral from the sending IP. The underlying causes are multifaceted, spanning poor list hygiene, high complaint rates, authentication failures (DMARC, DKIM), spammy content, low engagement, IP listing on blocklists like Spamhaus, and overall poor sender reputation. Resolving this involves addressing these root causes by implementing strict opt-in, regular list cleaning, complaint monitoring via feedback loops, ensuring correct SPF and DKIM alignment, improving content quality, boosting engagement, monitoring sender reputation, checking and delisting from Spamhaus if necessary, and reviewing Yahoo's sender best practices. Bounce messages may contain specific guidance, and contacting Yahoo support might be required.
Key findings
- Permanent Deferral: TSS09 errors lead to all emails from the IP being permanently deferred by Yahoo.
- Poor List Hygiene: Inactive or invalid addresses, lack of opt-in, and failure to honor unsubscribes contribute to TSS09.
- High Complaint Rates: Elevated spam complaint rates negatively impact sender reputation and trigger TSS09.
- Authentication Issues: DMARC failures, often due to SPF/DKIM misconfiguration, are a common cause.
- Spammy Content: Content with problematic keywords, excessive images, or poor formatting triggers spam filters and leads to TSS09.
- Low Engagement: Low open and click-through rates signal deliverability problems and contribute to the error.
- Spamhaus Listing: Being listed on Spamhaus directly impacts email delivery to Yahoo.
- Sender Reputation: A poor sender reputation is the culmination of various issues and significantly impacts deliverability.
- 5XX Error: TSS09 falls under the 5XX category, meaning messages are not delivered and should not be retried.
Key considerations
- Bounce Message Analysis: Check SMTP bounce messages for specific error details and links to Yahoo resources.
- Yahoo Best Practices: Thoroughly review and implement Yahoo's sender best practices to ensure compliance.
- Feedback Loop Monitoring: Monitor feedback loops to identify and remove subscribers who mark emails as spam.
- Spamhaus Delisting: If listed on Spamhaus, promptly follow their delisting procedures.
- Contact Yahoo Support: If issues persist after addressing the identified problems, contact Yahoo support for assistance.
- Proactive Monitoring: Implement proactive monitoring of sender reputation and engagement metrics.
- Avoid Spam Traps: Avoid spam traps to maintain a good sender reputation.
What email marketers say
7 marketer opinions
Yahoo's TSS09 error indicates a severe issue with email sending practices, resulting in permanent deferral of messages from the sender's IP. Common causes include poor list hygiene (inactive or invalid addresses, lack of opt-in), high complaint rates (spam reports), DMARC failures (SPF/DKIM misconfiguration), spammy content, and overall poor sender reputation. Resolution involves addressing these issues, reviewing Yahoo's sender best practices, and potentially opening a support ticket with Yahoo.
Key opinions
- List Hygiene: Poor list hygiene is a major contributor to TSS09 errors. Implement strict opt-in, regularly clean lists, and honor unsubscribes.
- Complaint Rates: High spam complaint rates can trigger TSS09. Monitor feedback loops (FBLs) and remove complainers.
- Authentication: DMARC failures due to SPF/DKIM misconfiguration can cause TSS09. Ensure proper authentication setup.
- Content: Spammy content, keywords, and formatting can lead to TSS09. Review content for potential issues.
- Sender Reputation: Poor sender reputation is a key factor. Maintain good reputation through consistent, engaging sending.
Key considerations
- Bounce Messages: Check SMTP bounce messages for links to Yahoo's sender support for specific guidance.
- Yahoo Best Practices: Review Yahoo's sender best practices to ensure compliance with their guidelines.
- Support Ticket: Consider opening a support ticket with Yahoo if issues persist after addressing common causes.
Marketer view
Email marketer from Mailgun Support notes that DMARC failures can lead to TSS09 errors. Ensuring SPF and DKIM are properly configured and aligned with the sending domain is crucial for passing DMARC checks.
29 Jul 2021 - Mailgun
Marketer view
Email marketer from EmailGeeks Forum suggests checking the SMTP bounce message for a link to Yahoo's sender support page. They recommend opening a ticket with Yahoo or having the customer correct their sending practices.
18 Feb 2022 - EmailGeeks Forum
What the experts say
3 expert opinions
Yahoo TSS09 errors, categorized as 5XX permanent errors, signify significant deliverability problems stemming from various factors. Key causes include invalid email addresses, authentication failures (DMARC/DKIM), unacceptable message content, suspicious sending patterns, poor engagement, IP listing on blocklists like Spamhaus, and overall low sender reputation. Resolving these errors necessitates proactive monitoring of sender reputation and engagement metrics, consistent authentication practices, meticulous list hygiene, and avoidance of spam traps. Retry attempts for emails resulting in 5XX errors are discouraged, and list managers should remove affected addresses.
Key opinions
- 5XX Errors: TSS09 is a 5XX permanent error; do not retry sending. List managers should remove affected addresses.
- Sender Reputation: Poor sender reputation is a primary cause. Requires consistent authentication, engagement, and list hygiene.
- Engagement: Low engagement rates contribute to TSS09. Proactive monitoring is crucial.
- Authentication Failures: DMARC/DKIM failures are a significant factor. Ensure correct configuration.
- Spamhaus Listing: IP listing on Spamhaus can cause TSS09 errors. Check and delist if necessary.
Key considerations
- Proactive Monitoring: Continuous monitoring of sender reputation and engagement is essential.
- List Hygiene: Maintain a clean list by removing invalid addresses and honoring unsubscribes.
- Spam Trap Avoidance: Avoid spam traps to maintain a good sender reputation.
Expert view
Expert from Word to the Wise explains that Yahoo TSS09 errors can be caused by a number of issues including low engagement, sender reputation problems, or potential blocklisting. She emphasizes proactive monitoring of sender reputation and engagement metrics to avoid triggering such errors.
7 Jul 2023 - Word to the Wise
Expert view
Expert from Email Geeks highlights the key points regarding 5XX permanent errors from Yahoo's sender best practices, including invalid email addresses, authentication failures (DMARC/DKIM), unacceptable message characteristics, suspicious behavior, or IP listing by Spamhaus. He advises against retrying sending emails with 5xx errors and recommends list managers remove such addresses.
28 May 2023 - Email Geeks
What the documentation says
4 technical articles
A Yahoo TSS09 error signifies permanent deferral of emails due to severe sending issues, including spam-like content, low engagement, and poor IP reputation. It's a 5XX error, indicating permanent failure, as per RFC 5321. This can also mean your IP is listed on Spamhaus. Resolution involves addressing underlying sending practices, checking and potentially delisting from Spamhaus, and reviewing Yahoo's sender best practices for authentication (SPF, DKIM, DMARC), list management, content quality, and engagement.
Key findings
- Permanent Deferral: TSS09 results in all messages from the IP being permanently deferred by Yahoo.
- Root Causes: The error indicates significant issues like spam-like content, low engagement, or poor IP reputation.
- 5XX Error: As per RFC 5321, TSS09 falls under the 5XX category, meaning the message cannot be delivered and should not be retried.
- Spamhaus Listing: The IP might be listed on Spamhaus, contributing to the delivery issue.
Key considerations
- Address Underlying Practices: Focus on improving sending practices, including content quality and engagement strategies.
- Spamhaus Check: Check IP reputation on Spamhaus and follow delisting procedures if necessary.
- Yahoo Best Practices: Review and adhere to Yahoo's sender best practices, covering authentication, list management, content, and engagement.
Technical article
Documentation from Yahoo Postmaster recommends reviewing their sender best practices guidelines to ensure compliance. Key areas include authentication (SPF, DKIM, DMARC), list management, content quality, and engagement monitoring.
11 Jun 2024 - Yahoo Postmaster
Technical article
Documentation from Spamhaus indicates that a TSS09 error might be related to the sender's IP being listed on Spamhaus. Senders should check their IP reputation on the Spamhaus website and follow their delisting procedures if necessary.
6 Oct 2021 - Spamhaus
How can I resolve Yahoo SMTP error 421 4.7.0 TSS04?
How can I troubleshoot and resolve Yahoo TSS04 email errors?
How many retries should I send to Yahoo after receiving a temporary error?
What are TSS04 errors and how do I fix them?
What does Yahoo bounce code RL02 mean?
Why am I getting TSS04 errors from Yahoo and how do I fix it?
