How to Validate Yahoo email address without sending

Syerks

Greylisted
I have some list and did a good job through a python script by validation mailboxes for major ISPs like Gmail, AOL, etc., but I have some troubles with Yahoo, since it accept all rcpt to commands and is waiting for a data.

Did someone tried to validate Yahoo addresses without emailing to them?

Please advice.
Thanks
 

EQ Admin

EQ Forum Admin
Staff member
Hello,

There is nothing wrong with sending the Yahoo accounts on your list a "reconfirm" message asking them to verify they want to still be on your list before continuing to send them your newsletters. Drop anyone from your list who doesn't reconfirm they want to be on it. If that generates a high spam/unsubscribe rate there is something wrong with the original list anyways.

:welcome: to Email Questions
 

Syerks

Greylisted
Thanks for your answer. I do understand and agree with your position, however it is still very interesting from a tech perspective how major List Cleaning companies blame that they do verify addresses. Or they are simply provide with wrong info.


Thanks for advise.
 

EQ Admin

EQ Forum Admin
Staff member
List cleaning companies are for spammers.

If you need a list cleaning company you should start over and create new lists.
 

EQ Admin

EQ Forum Admin
Staff member
As for manual and scripted checks, Yahoo is dropping me faster than I can HELO.

I got to start mail from a couple times before being dropped but usually get dropped at HELO.

;; ANSWER SECTION:
yahoo.com. 1800 IN MX 1 mta5.am0.yahoodns.net.
yahoo.com. 1800 IN MX 1 mta7.am0.yahoodns.net.
yahoo.com. 1800 IN MX 1 mta6.am0.yahoodns.net.

I'm currently seeing these as the MX servers.

I tried several connections to each since all of those names have multiple A records associated with them.
 

Syerks

Greylisted
Yes, they have very quick connection drop. So you may use some scripts to make a check or just use the same from as a rcpt to. Example:

telnet mta7.am0.yahoodns.net 25
Trying 66.196.118.33...
Connected to mta7.am0.yahoodns.net.
Escape character is '^]'.
220 mta1069.mail.bf1.yahoo.com ESMTP YSmtpProxy service ready
helo hi
250 mta1069.mail.bf1.yahoo.com
mail from: <badaddred@yahoo.com>
250 sender <badaddred@yahoo.com> ok
rcpt to: <badaddred@yahoo.com>
250 recipient <badaddred@yahoo.com> ok

So after rcpt to Yahoo is waiting for a data and only after a data it will reply you
554 delivery error: dd This user doesn't have a yahoo.com account

So there is some other way to validate email address.

I am just curious how {email validation sites} know about why email is bad(invalid). Thought someone will help me with this here.

Btw, thanks for your quick replies.
 

EQ Admin

EQ Forum Admin
Staff member
Hello,

This isn't something that I have tried to script out.

If I did it would be with perl. Maybe it would be a fun thing to try :)

With php here is an example of how someone did it specifically for Yahoo not using SMTP:

{ old broken link removed }

So, that makes the answer to your question, maybe the sites you are asking about are using other validation checks such as web calls looking for the existence of profile pages etc?
 
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