Yahoo rejects your e-mail messages ( 421 )

Hello everyone,

This article is intended for people having problems with Yahoo mail not accepting e-mail messages at all.
Please note that this article is not intended to help you delivering e-mail messages to the Yahoo Inbox folder, that is impossible, unless you have enough money to pay Yahoo. You may fine a lot of articles on the internet that will tell you how to deliver mail to the Yahoo Inbox instead of Spam, some may help but expect a 10 to 20% chances of success.

When Yahoo drops e-mail messages you will usually see the message below in your logs:

421 4.7.1 [TS03] All messages from will be permanently deferred; Retrying will NOT succeed. See
Connection closed by foreign host.

First thing you need to do is to follow the link in that log message:
Of course that link does not work directly (most likely a bad configuration at Yahoo) but it will take you to a page with different links and one of them is the right one:

Looking at that link, you will notice the following two lines:

"This error message indicates we are seeing a high volume of messages from your IP address that is a characteristic of unsolicited, bulk emails. "

In 99% of all cases this is not true. Yahoo sends that message for new IPs too (they don't really care about consistency or if you can or can't send e-mails to them unless you pay them).
Going further you will end up on this link:
In the following lines I will try to help you complete that form. Please submit and suggestions to our query e-mail address.

Please note, you should not play around with this form and write a nickname, use your real details where necessary otherwise they will refuse your query and will block you for the next 6 months.

So here is the form (comments are written in brown):

Your Name: your real name

Your Role: a role if you have any , leave blank afterwards

Email Address:
your e-mail address, make it a real one 

Confirm Email Address 
confirm it

Company Name:
if you have any, leave blank otherwise 

Company Website:
if you have a website (you need and should, try no warez sites) 

Postal Address:
use real data 

Phone #:
try to use real data 

Mailing Information:
For each of your active mail servers, please provide the IP address, the reverse DNS record, and the domain associated with it. One mail server entry per line. (See sample entry in the text box.)

You need to add your VPS IP address with the mail server name (you can find that by telnetting to your VPS IP: telnet 25 )
Note that the server name needs to be a valid hostname like where is your domain (localhost or localhost.localdomain is not ok). Check if the ping works to, if it does not you need to configure that sub domain and also the rDNS to point to that sub domain.

Do you use an Email Service Provider (ESP)?
We are an ESP sending emails for our client(s).
No, we send our own emails.
- correct answer 
If you do use an ESP, which one?

leave blank

Do you use dedicated or shared IP addresses?

Dedicated IPs (is. only our company sends from these IPs)

Do you sign emails with DomainKeys/DKIM?

DomainKeys only. If you do not have domain keys you should enable them. It is not really necessary right now since they can't verify but will help in the future. 

What type of emails are sent from your IP addresses?

You can answer below depending on the types of e-mails you send. 
Forum Postings
Personal/Corporate Emails
If other, please specify:

What subscription process do you utilize?:
Confirmed/Double Opt-In
Single Opt-In
Affiliate Marketing
If other, please specify:

You can answer depending on what/how much you send
Additional Subscription Information:
How many subscribers do you currently have?

How many emails do you send on a monthly basis?

Please note, the URL needs to be in english and needs to exist. Otherwise just create a PP page from someone else and copy & paste it to your page. Also, regarding the English language, if your PP page is in a different language send Yahoo the google translated page's URL otherwise they will not read your web page. 
Privacy Policy URL:

Subscription Form URL: (Optional)

List Maintenance:
Do you remove bouncing email addresses from your subscription list?
If you do remove bouncing email addresses, how many Soft bounces (4xx) does it take to be removed from you list? (Optional)

If you do remove bouncing email addresses, how many Hard bounces (5xx) does it take to be removed from you list? (Optional)

How long does it take for an email address to be removed from your list once an unsubscribe request has been recieved?
1 hour (or similar)

Additional Information:
Describe in detail any problems you are currently experiencing when sending emails to Yahoo! Mail -- e.g., getting frequent deferrals, emails landing in the Spam folder. Please include any SMTP error message(s) you are getting from our mail servers or the complete headers of an email that was delivered to our Spam folder.


After you complete this form, submit it to yahoo and wait for an answer for about 24-48 hours. Please note that if they send you a reply that contains the form, you will have to reply to them with the form completed in that reply. For some reason they do not seem to process the form correctly some times.

If everything is ok you should receive an answer that your IPs are now whitelisted. This does not mean that your e-mail messages will all end up in Inbox.

Thank you,
The IntoVPS team

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