Monday, June 7, 2010

Net neutrality: Our experience with Yahoo email blocking

More than two years trying to get off Yahoo spam list, and they're still blocking our email. Latest message to hundreds of our emails is: host[] refused to talk to me: 421 4.7.1 [TS03] All messages from will be permanently deferred; Retrying will NOT succeed. See


Anonymous said...

We had a similar problem which we managed to mostly resolve with this fix:

you'll need to add a spf record to your dns server.


Moderator said...

Yahoo is again blocking all our email. Here's what we get back with every mail (we've hidden the email address):

From: Mail Delivery Subsystem
Subject: Returned mail: see transcript for details

This is a MIME-encapsulated message


The original message was received at Wed, 22 Dec 2010 15:21:31 -0500
from [] (may be forged)

----- The following addresses had permanent fatal errors -----

----- Transcript of session follows -----
... Deferred
Message could not be delivered for 5 days
Message will be deleted from queue

Content-Type: message/delivery-status

Reporting-MTA: dns;
Arrival-Date: Wed, 22 Dec 2010 15:21:31 -0500

Final-Recipient: RFC822;
Action: failed
Status: 4.4.7
Remote-MTA: DNS;
Last-Attempt-Date: Mon, 27 Dec 2010 15:38:00 -0500

Content-Type: message/rfc822

Received: from [] ( [] (may be forged))
(authenticated bits=0)
by (8.13.8/8.13.8) with ESMTP id oBMKLUg2026775
for ; Wed, 22 Dec 2010 15:21:31 -0500
User-Agent: IntelliMerge 5.1