On the Yahoo blacklist? Can’t send email to Yahoo?

Trust me, you are not alone.

Yahoo, Google, AOL, ATT and other ISPs are often targets of spammers. If you have a security issue on your server, you likely will get blacklisted by one of these major ISPs.

Below I go over our process to removal your server’s IP from the Yahoo blacklist.

Yahoo Email Blacklist Policy

Yahoo! does reveal their blacklist practices, but they like most email service providers use your sender’s IP reputation to determine if your email gets though.  Here are just a few of the items know to impact your server’s sender reputation.

  • Blacklistings
  • Bounce rates
  • Email Sent to Unknown Users
  • Total Email Volume
  • IP Neighborhood
  • Email Volume
  • Complaint Rates
  • Spam Trap Hits
  • Changes in Email Volume
  • History of IP Address

Before beginning any blacklist diagnostics, I recommend you check your server’s IP reputation at SenderScore.org.  If you have a score less than 80, then you may have email delivery issues.

Common problems we see are:

  • Compromised user account used to send spam.
  • Web application exploit used to send spam.
  • Bulk emailing from mailing lists, newsletters, forums & blogs (even if they are opt-in).
  • Bulk forwarding of email to Yahoo.

The last one is often overlooked.  If you forward email to Yahoo and you then mark it as spam, Yahoo will penalize your server.  This is often a problem on shared hosting servers.  Some user will just forward all of their email to Yahoo.  These are often junk accounts that receive 100’s of spam messages.  If you get your server off of the blacklist, then you will likely need to stop this practice.

Yahoo! Mail & cPanel

Yahoo does not like cPanel very much.   Exim’s default configuration on can trigger about 150 retry attempts per initial failure.  The high number of retries causes your Yahoo to suspect your server of sending spam.  You need to adjust the retry limits to fix this.  See the 1 Big Reason Yahoo! Defers Email from cPanel for the full details.

Yahoo Blacklist Check

Unlike like Spamhaus, Spamcop and other public real time blacklist (RBLs), you cannot simply lookup an IP at Yahoo! to see if it is blacklisted.  Typically, the only way you know email is rejected is you will get a message like this:

421 4.7.0 [TS01] Messages from <> temporarily deferred due to user complaints

<> ;see http://postmaster.yahoo.com/421-ts01.html

There are other variations such as:

553 5.7.1 [BL21] Connections will not be accepted from,

because the ip is in Spamhaus's list; see <a href="http://postmaster.yahoo.com/550-bl23.html">http://postmaster.yahoo.com/550-bl23.html</a>


The important part is the specific error code, such as “BL21” or “TS01“.  These along with the link will tell you the specific SMTP error that Yahoo! is returning.  Always check this list of Yahoo’s SMTP Error Codes so you know exactly why you are listed.  You can find the specific codes in the email bounce you receive when your message cannot be delivered.

Fix the Problem

Your server is blacklisted for a reason. If you don’t find that reason, you will just be blacklisted again.
Before you try to request removal, be sure to analyze your server to find out why you were listed in the first place. You have to fix the issue or they will just list your server again.

Do not try to get removed from the blacklist if you have not found the source of the problem. You don’t want cycles of delisting and re-listing to damage your sender reputation. If you have found the problem, then simple wait. In many cases, I find that the block is removed in under 48 hours.

Don’t forget DNS. 

Make sure that:

  • Reverse DNS  resolves to a hostname.
  • Make sure the hostname has a A record.
  • Don’t use generic hostnames assigned by ISPs or server vendors.
  • SPF is valid.
  • DKIM is working properly.

DNS is one of the most critical elements to good email delivery, so always fix DNS issues as they could be why you are blacklisted in the first place.

Yahoo Blacklist Removal Instructions

Check Spamhaus

Yahoo uses Spamhaus.   Make sure you are not listed there.  If you are then you need to request removal from  Spamhaus before you contact Yahoo!.  You may find that once you are removed from Spamhuas, your email to Yahoo! will start flowing again.

Yahoo Bulk Sender Form

Even if you are not a bulk sender, you will need to complete the  Yahoo! Bulk Sender Form.

Though some fields on the delivery report are optional, it is best to provide as much information as possible. Especially, the “Enter additional information here:”.

You will want to detail in 2-3 sentences your remediation efforts.

For example, if the problem was a compromised web script send them a note:

We have identified an insecure web application on our server that permitted unauthorized email relay through our system. We have removed this script.

Keep it short and technical. Yahoo! postmaster staff reviews 1000’s of these requests, so being short and to the point is best to get removed from the Yahoo blacklist.