Don't validate some existent email

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Validate a large group of email
2.
3.

What is the expected output? What do you see instead?
Validation of correct and existent email.
Instead I see that a lot of existent email address don't be validated (400
of 800).

What version of the product are you using? On what operating system?
last

Please provide any additional information below.
Email addresses not validated  are a lot of email of my friend, so I'm sure
these are valid!
I used the code of the second example.

Original issue reported on code.google.com by golb...@gmail.com on 26 Apr 2010 at 7:52

[GoogleCodeExporter]

Hello,

I have the same problem I tested this script on my list (around 9 000 optins 
emails with 3, 4 or 5 stars on mailchimp) and some of these are invalid...

I tested with my all personal emails and 0 are valid (around 8/9 emails...)

Original comment by thibaut....@gmail.com on 8 Dec 2014 at 2:19

[GoogleCodeExporter]

I just tested my own email address with Win7/XAMPP/Eclipse and it is BAD.

Debugging says

>>>
HELO localhost

<<<
250 mta1663.mail.gq1.yahoo.com

>>>
MAIL FROM: <user@localhost>

<<<
553 5.7.1 [BL21] Connections will not be accepted from 24.95.38.206, because 
the ip is in Spamhaus's list; see http://postmaster.yahoo.com/550-bl23.html

>>>
RCPT TO: <twidlar@yahoo.com>

<<<

The Yahoo page https://help.yahoo.com/kb/postmaster550-bl23.html is NOT FOUND.

Original comment by twid...@gmail.com on 24 Dec 2014 at 3:08

[GoogleCodeExporter]

I went to Spamhaus' site. After I looked up my IP I found the all Time Warner's 
dynamic IPs are blocked. So I will have to upload to my remote site and try.

Original comment by twid...@gmail.com on 24 Dec 2014 at 4:19