Problem:
You send an email to a Yahoo email account and it is returned to you with a "421 Message Deferred Message"

Discussion:
This is normal Yahoo. It happens no matter what mail server you use. Yahoo treats any email from the outside as if it were spam.

You may notice that only certain email addresses are unable to send email to Yahoo addresses. Alternatively, it may be your entire domain that can't send email to Yahoo. Either way it is caused by mail being reported as SPAM coming from your domain. Once reported, you are blocked. There are no second chances. The steps to get your domain or email addresses unblocked are time consuming and frustrating. Especially with the slow responses you get back from Yahoo Technical support. SubStorm will help you through this process the best we can.

Resolution:
First, you need to determine if your entire domain is blocked, or just certain users. Try sending emails to Yahoo from a majority of your accounts to determine this.

Next, grab copies of a few sample emails that were bounced back. We need the original message that was sent out and the message that bounced back.

Finally, contact SubStorm and notify us of the problem so we can begin the process.

PLEASE NOTE:
This may take several weeks to resolve. It's dependent on how quickly Yahoo responds to our requests.