The Spamhaus Project


Erroneous Mail Rejections at Yahoo!

by The Spamhaus TeamMay 30, 20092 minutes reading time

During the last week of May, 2009, some senders experienced mail rejected by which referenced Spamhaus PBL data. But when they looked up their IP address, it was not in any Spamhaus list. The error was not consistent, and sometimes resubmitting a message might result in its delivery. Yahoo! is aware of the problem and made this announcement on its postmaster list (Wed May 27, 2009):

We have received reports that some senders are seeing intermittent IP blocks when sending to Yahoo! Mail, with the SMTP error message from us citing that the block was due to a Spamhaus listing -- e.g., "553 5.7.1 [BL21] Connections not accepted from IP addresses on Spamhaus PBL." (See our full list of SMTP error messages at .)

If your IPs are currently not listed on any Spamhaus blocklist but you are seeing this error, please be assured that we are looking into the matter. We shall post an update once we have resolved the issue.

If you have any doubt whether your IP is listed in any Spamhaus list, our lookup form provides the correct and authoritative answer. If your IP is listed, our website provides links to further information. If it's not listed then we can't offer further assistance.

Other Spamhaus pages that might also be of interest to those who experienced such a problem:

Update: Yahoo! has announced on its postmaster list that they have resolved the problem:

Thursday, June 4, 2009 11:53 AM

We have rolled out a patch this morning that addresses the spurious Spamhaus blocks described in our prior post. We are confident that this latest push resolves the problem. We are still in the process of making sure all our MTAs received the update, but for the most part, the issue should no longer be prevalent (as of 10am PDT).

We certainly appreciate your patience during the past few days. If you encounter further issues, please free to let us know us via http://postmaster. (click on the "Contact Us" tab).

Update: 2009-07-16: Yahoo! identified two machines (out of many total mail servers) which recently exhibited the erroneous rejections and they are correcting the errant configuration.

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