Email Delivery Issues – Updated 11/4/2024 9:17pm PST

The Cat House on the Kings is still working to resolve email delivery problems with domains that use Yahoo! email servers. If your email address is not in one of the listed domains, you probably aren't affected by this issue.

Affected Domains

What you need to know

1. Yahoo! email servers continue to defer delivery of messages sent through the email server that is on the same server as our website.
2. We have used the same software and configuration for years, but something changed at Yahoo in September this year. We have received no help whatsoever from Yahoo to resolve this problem.
3. We have mitigated the problem to the extent possible by changing to a third party email delivery service for messages to our mailing list as well as individual emails generated by our website.
4. The remaining messages from our team to individuals is still being delayed. We are working towards moving our entire email service away from our current hosting provider, but that will take some weeks to accomplish. In the meantime if your email address is in one of the affected domains, please try to contact us through a different address. Otherwise messages we send may not reach you.

The gory details, if you care

The root cause of the problem was identified by someone else as far back as 2019. Yahoo advertises multiple mail servers, each with more than 10 IP addresses. When one of those servers rejects a message with a temporary error, the email software on our end rapidly tries a number of the alternate server IP addresses. This causes Yahoo to detect that it may be being attacked and blocks mail delivery requests.

We don't understand why this only became a problem in September 2024 after years of uninterrupted service and no configuration or software change on our end.

Although the original article identifies a potential work around, we have found that the current version of the software ("cPanel") that manages the mail software ("exim") requires the required configuration change be made through their software because the configuration is rebuilt each time the service is (re)started. Unfortunately there is a bug in the cPanel software such that any attempt to edit the configuration section for the workaround results in the modified section being added to instead of replacing the existing section, causing a configuration error. So we are prevented from implementing the workaround to the Yahoo! problem.

So we have mail software ("exim") that is triggering an attack response from Yahoo, but we can't change its behavior with the recommended workaround because of a bug in the cPanel software.

Questions or comments?

Please email webmaster@cathouseonthekings.com.