Starting today, I've been seeing emails I send to recipients at comcast.net bounced like this:
This is an automatically generated Delivery Status Notification. Delivery to the following recipients failed permanently: * [Removed for forum post] Reason: There was an error while attempting to deliver your message with [Subject: "Re: phone"] to [Removed for forum post]. MTA p3plsmtpa06-01.prod.phx3.secureserver.net received this response from the destination host IP - 18.104.22.168 - 554 , 554 5.1.0 22.214.171.124 Comcast block for spam. Please see http://postmaster.comcast.net/smtp-error-codes.php#BL000000 .
I looked up the error message on Comcast's help page, and it says "Our filters have determined that email from your email server has been sent in patterns which are characteristic of spam. In an effort to protect subscribers, your email server has been blocked from sending email to the Comcast network."
I looked up the IP addresses, and it really is Comcast blocking mail from GoDaddy servers.
Is anybody else seeing this? Comcast is a huge ISP - GoDaddy must know about the problem. Has anybody else heard anything?