Why am I seeing an influx of TS errors from Yahoo?
Summary
What email marketers say15Marketer opinions
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.
Marketer from Email Geeks confirms that they are seeing more Yahoo TS errors than usual.
Marketer from Email Geeks shares they saw the Yahoo TS errors starting yesterday evening around 6:00pm Eastern. They are not seeing any bounces and the connections are maintaining but errors every few minutes for high engaged senders. They also seem to be coming from the same few MX records.
Email marketer from Kickbox.com explains that if end users are reporting your email as spam in increased numbers, Yahoo will throttle you and give temporary errors.
Email marketer from Email Validation Service shares that a sudden increase in TS errors could be due to sending to a large number of invalid or inactive email addresses. Cleaning your email list regularly can help improve deliverability.
Email marketer from Reddit shares the Yahoo TS errors may happen because Yahoo is aggressively throttling email traffic from certain senders.
Email marketer from Email Deliverability Experts explains that Yahoo may be experiencing increased content filtering which can cause temporary server issues if your email triggers spam filters more frequently.
Email marketer from Email Deliverability Blog shares that if you're on a shared IP address, the actions of other senders can impact your deliverability and potentially lead to TS errors if their reputation is poor.
Email marketer from Mailgun Community responds the Yahoo TS errors may occur after sending a particularly large email campaign, indicating that Yahoo's servers are temporarily overwhelmed by the volume.
Email marketer from Email Marketing Tips Blog shares that an increase in Yahoo TS errors might be due to issues with your SPF records or other email authentication methods. Make sure your authentication is correctly configured.
Marketer from Email Geeks shares they are seeing the same issue for all VMG domains, with more throttling than normal.
Marketer from Email Geeks noticed that Verizon Media Group is currently switching their serves back and forth from MTA to ATLAS.
Marketer from Email Geeks shares that they are seeing a flood of MTA backoff notifications but messages are delivering and queues aren't backing up.
Marketer from Email Geeks explains that even when going easy on sending, they are still getting the Yahoo TS errors. They also saw the issue starting yesterday afternoon and into the night to start again today in the am.
Email marketer from EmailGeeks Forum responds that a sudden increase in Yahoo TS errors might indicate a potential hit to your sending reputation with Yahoo.
What the experts say2Expert opinions
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.
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.
What the documentation says5Technical articles
Documentation from SparkPost responds that Yahoo is trying to protect its network and that throttling is common to protect their end users.
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.
Documentation from Microsoft explains that temporary issues on the recipient's email server can result in a TS error. These errors are often resolved automatically, and no action is required.
Documentation from RFC defines that SMTP server response codes in the 4xx range (like temporary system errors) indicate that the message was not accepted for delivery, but the error is transient and retrying may be successful.
Documentation from Postmark explains that TS errors can occur during high traffic times when servers are overloaded and unable to process requests quickly enough to maintain normal speeds.