Summary
The influx of TS errors from Yahoo is a multifaceted issue, likely stemming from a combination of factors. Many email marketers reported experiencing these errors concurrently, suggesting a widespread event rather than isolated incidents. Key contributing factors include potential Yahoo infrastructure changes or maintenance, aggressive throttling of email traffic, possible reputation degradation, problems with SPF records or email authentication, increased content filtering, Yahoo server overload during large campaigns, and the impact of being on a shared IP address where other senders' activities affect deliverability. Temporary rejections such as greylisting and connection limits are employed. A shift in reputation is also indicated, and you should reach out to Yahoo postmaster. Furthermore, sending to invalid email addresses or increased spam reports can trigger these errors. Documentation suggests Yahoo mail servers may be experiencing technical difficulties. Finally, the Verizon Media Group's server switching between MTA and ATLAS might also play a role. These temporary errors are often transient and may be resolved automatically.
Key findings
- Widespread Occurrence: Numerous email marketers report a simultaneous surge in TS errors from Yahoo.
- Infrastructure Changes: Potential infrastructure changes or maintenance on Yahoo's end.
- Aggressive Throttling: Aggressive traffic throttling by Yahoo.
- Reputation Impact: A decline in sending reputation is a possible cause.
- Authentication Issues: Problems with SPF or other email authentication records.
- Content Filtering: Increased or stricter content filtering by Yahoo.
- Server Overload: Server overload due to high-volume sending campaigns.
- Shared IP Impact: Negative impact from other senders on shared IP addresses.
- Technical Issues: Yahoo mail servers may be experiencing technical problems.
- Reputation: Temporary rejections are used to monitor reputation.
- List Hygiene: Sending to invalid addresses or increased reports of spam.
- VMG issue: VMG's MTA/ATLAS switch may affect deliverability.
Key considerations
- Monitor Reputation: Closely monitor sending reputation with Yahoo and other providers.
- Verify Authentication: Double-check and ensure correct configuration of SPF, DKIM, and DMARC.
- Review Content: Review email content for potential spam triggers.
- Manage Sending Volume: Gradually increase sending volume, avoiding sudden spikes, especially during large campaigns.
- Practice List Hygiene: Regularly clean email lists to remove invalid or inactive addresses.
- Contact Yahoo Postmaster: Contact Yahoo Postmaster to obtain specific details about the reasons for the errors.
- Be aware of VMG Domains: Be aware of MTA/ATLAS changes on Verizon Media Group (VMG) domains.
- Retry: Retrying is likely to work.
What email marketers say
15 marketer opinions
The influx of TS errors from Yahoo appears to be a widespread issue, with various factors contributing to the problem. Several email marketers reported experiencing these errors around the same timeframe, suggesting a potential systemic issue. Possible causes include: Yahoo infrastructure changes, aggressive throttling, reputation issues, authentication problems (SPF records), increased content filtering, temporary server overloads due to large campaigns, shared IP reputation impacts, issues around VMG domains switching from MTA to ATLAS and sending to invalid email addresses or spam reports. Verizon Media Group’s server switching between MTA and ATLAS could be contributing. It's important to note temporary errors are common and may be resolved over time.
Key opinions
- Widespread Occurrence: Multiple email marketers have reported a sudden increase in TS errors from Yahoo around the same period, indicating a broader issue rather than isolated incidents.
- Potential Infrastructure Changes: Yahoo may be undergoing infrastructure changes, causing temporary disruptions and leading to TS errors.
- Aggressive Throttling: Yahoo might be aggressively throttling email traffic, resulting in TS errors for senders.
- Reputation Impact: A sudden rise in TS errors could indicate a decline in the sender's reputation with Yahoo.
- Authentication Issues: Problems with SPF records or other email authentication methods could contribute to the errors.
- Content Filtering: Increased content filtering by Yahoo may trigger spam filters more frequently, leading to TS errors.
- Server Overload: Large email campaigns can overwhelm Yahoo's servers, causing temporary errors.
- Shared IP Impact: Senders on shared IP addresses may be affected by the actions of other senders with poor reputations.
- List Hygiene: Sending to invalid or inactive email addresses can trigger increased TS errors.
- VMG Server Switch: Verizon Media Group's server switch between MTA and ATLAS might be related.
Key considerations
- Monitor Sending Reputation: Actively monitor your sending reputation with Yahoo to identify any potential issues or declines.
- Verify Authentication: Ensure that your SPF records and other email authentication methods are correctly configured and up to date.
- Review Content: Examine your email content to ensure it is not triggering spam filters.
- Gradual Sending: Avoid sending large email campaigns suddenly. Gradually increase sending volume to prevent overwhelming Yahoo's servers.
- List Hygiene: Regularly clean your email list to remove invalid or inactive addresses and reduce bounce rates.
- Check for VMG issues: If sending to VMG domains, be aware of potential disruptions from the MTA/ATLAS server switch.
- Check with Yahoo: If issues persist, contact Yahoo postmaster support.
Marketer view
Email marketer from Stack Overflow suggests that an influx of TS errors from Yahoo could be due to Yahoo making infrastructure changes that affect email sending.
5 May 2025 - Stack Overflow
Marketer view
Marketer from Email Geeks confirms that they are seeing more Yahoo TS errors than usual.
14 May 2025 - Email Geeks
What the experts say
2 expert opinions
Experts suggest that an influx of TS errors from Yahoo could be due to various temporary rejection methods employed by Yahoo to evaluate message content and sending IP reputation. These methods include greylisting, exceeding connection limits, and exceeding the number of messages allowed per connection. A sudden increase in TS errors can also indicate a shift in your sending reputation with Yahoo. It's advised to monitor signals and reach out to Yahoo's postmaster to understand the specific reason for the errors.
Key opinions
- Temporary Rejections: Yahoo employs temporary rejections like greylisting, connection limits, and message limits to evaluate email delivery.
- Reputation Shift: An increase in TS errors can signal a change in your sending reputation with Yahoo.
- Evaluation Methods: These rejections are used to slow down delivery and allow time to evaluate message content and IP reputation.
Key considerations
- Check Postmaster: Contact Yahoo's postmaster to determine the specific reason for the TS errors.
- Monitor Signals: Monitor your sending signals, such as bounce rates and spam complaints, to identify potential reputation issues.
- Connection Limits: Review your sending practices to ensure you are not exceeding connection or message limits.
- IP Reputation: Examine your IP reputation with Yahoo.
Expert view
Expert from Spam Resource explains that the most common temporary rejections are greylisting, exceeding connection limits, and exceeding the number of messages allowed per connection. All of these are methods to slow down delivery to allow time to evaluate the message content and sending IP reputation. Check with the recipient’s postmaster to verify the reason.
4 Aug 2022 - Spam Resource
Expert view
Expert from Word to the Wise shares that a sudden increase of TS errors, or any increase in throttling, could indicate that there has been a shift to your reputation. Monitor the signals you can, and reach out to the provider to ask what's going on.
17 Nov 2024 - Word to the Wise
What the documentation says
5 technical articles
According to documentation from various sources, TS errors (Temporary System Errors) typically indicate temporary technical issues on the recipient's (Yahoo's) mail servers, such as server overload, maintenance, or high traffic. These errors are transient, meaning retrying delivery may be successful. Throttling is common to protect end users.
Key findings
- Temporary Issues: TS errors primarily signify temporary technical issues on Yahoo's mail servers.
- Transient Nature: These errors are transient, implying that retrying delivery may be successful.
- Potential Causes: Server overload, maintenance, and high traffic are potential causes of TS errors.
- Throttling: Throttling may occur to protect end users
Key considerations
- Retry Delivery: Given the transient nature of TS errors, retry sending the email.
- Monitor Error Rates: Monitor your error rates to detect any persistent issues beyond temporary server problems.
- Check Server Status: Consult Yahoo's help resources or postmaster information for updates on server status, although real-time information is limited.
- Address Underlying Issues: Consider other possible causes, such as reputation issues, if the issue persists.
Technical article
Documentation from SparkPost responds that Yahoo is trying to protect its network and that throttling is common to protect their end users.
14 Oct 2024 - SparkPost
Technical article
Documentation from Yahoo Help explains that TS errors (Temporary System errors) usually indicate that the Yahoo mail servers are experiencing technical issues, are temporarily overloaded or are currently under maintenance.
19 Apr 2025 - Yahoo Help
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