Ntlworld blocking mails

nilo.losbanos · 14-12-2004, 10:56

Hi,

Ntlworld has been rejecting my mails for the past few days. The error message doesnt indicate the reason why the mails were rejected. Any way of knowing if my mail-servers are in NTL's blacklist? Thank you.

-------------------------
Connected to smtpin.ntlworld.com, Port 25.
220 ESMTP server ready
250 aamta03-winn.mailhost.ntl.com
250 Sender <xyz@bigfoot.com> Ok
250 Recipient <xyz@ntlworld.com> Ok
354 Ok Send data ending with <CRLF>.<CRLF>
452 Message rejected
-------------------------

nostra · 14-12-2004, 11:06

http://www.dnsstuff.com/tools/ip4r.ch?ip=212.250.162.8

have heard people sending mails to yahoo or lycos (cant remember which one) are having problems a person who contacted the company had advised them that the ntl smtp was blacklisted

if you look into it...

Quote:

2004/Dec/08 17:06:17 UTC Removal Requested Requestor IP: 80.4.224.7/81.96.207.230
2004/Dec/09 17:15:07 UTC Removed
2004/Dec/11 00:59:32 UTC Listed in Unconfirmed (view message)
2004/Dec/11 00:59:32 UTC Listed in Multihop (view message)

ntl were removed from the blacklist on the 9th and put back on it on the 11th!

this blacklisting seems stupid to me the test was sent my an ntl customer so how does this prove that ntl is operating an open relay?

Quote:

IP: 212.250.162.8
Input IP: 81.100.84.35
Transport: smtp
Message Received: 2004/12/11 00:59:32 UTC
Message Sent By: anfi

Name: cpc3-cmbg3-3-0-cust35.cmbg.cable.ntl.com
Address: 81.100.84.35

as you can see this is an ntl customer which their smtp server would allow access too! this does not show that ntlworld is an open relay :@

nilo.losbanos · 14-12-2004, 11:30

oh, what I mean to say is that it might be that my smtp are the ones being blacklisted by NTL.

Is there a way of knowing if my smtp are really in ntl's blacklist? Or is NTL using third-party blacklists listed in dnsstuff, like sorbs or spamhaus?

nostra · 14-12-2004, 11:38

put your smtp server ip address on the spam database lookup at www.dnsstuff.com and that will tell you where it is blacklisted

i believe that ntl uses spamhaus sorbs etc

you arent using your ntl connection to host an smtp server are you?

this is going to be blacklisted as ntl broadband connections are dynamic ip addresses this means that it will be blacklisted due to the fact it is a dynamic ip address

nilo.losbanos · 14-12-2004, 12:05

My servers are not hosted in ntl. Some of my recipients are using ntlworld addresses.

I am hoping that someone from ntl will confirm that my servers are indeed in their blacklist. I made some several email tests and found out that some of my recipients(from ntl) didnt encounter any problem in receiving mails. It might not be a blacklist issue after all. I am not sure.

rdhw · 14-12-2004, 12:06

Quote:

Originally Posted by nilo.losbanos

Ntlworld has been rejecting my mails for the past few days.

Please be clear what you mean by this. Does "my mail" mean mail sent by your mail client connected to an NTL cable connection, or does "my mail" mean mail addressed to your ntlworld account from the outside world?

Quote:

Any way of knowing if my mail-servers are in NTL's blacklist?

What do you mean by "my mail-servers"? Where exactly in the world are these "mail servers"?

Quote:

250 Sender <xyz@bigfoot.com> Ok

I think bigfoot here might be your problem.

nostra · 14-12-2004, 12:25

and have you run your mail servers ip address through the blacklist checker to see if it comes up in any blacklist?

and a little more information on your setup and what you are actually trying to send from where would be helpful

nilo.losbanos · 14-12-2004, 13:39

nostra,

The ip addresses are listed in some blacklists. I think I have to clear up with these lists first, then contact NTL if the problem still persists. thanks.

sheka · 14-12-2004, 14:38

See my comments in

http://www.cableforum.co.uk/board/sh...ad.php?t=21218

It does appear that NTL are blocking mails sent to ....@bigfoot.com and not sending a response back to the mail originator......

sheka · 14-12-2004, 14:53

Your first post looks like you are trying to send some email using NTLWorlds smtp servers.

So you have connected and then stated the destination mail address and the originators mail address as ......@bigfoot.com.

You then enter the text of the email and the the mail gets refused with a 452 error.

SMTP error
452 = Requested action not taken: insufficient system storage

Sounds like your IP address is in a blacklist somewhere that NTL are referencing and then rejecting your mail attempts. Why some mails get through and other don't....maybe the blacklists on the SMTP servers are at varying levels of update?

Matth · 14-12-2004, 22:30

452 seems to be defined as "insufficient storage", not sure if that means the server is in trouble, or the recipient has allowed their mailbox to overflow.

The other thing, it appears that your dialog is talking DIRECTLY to an NTL SMTP server for delivery to an NTL account, from a non-NTL account - wrong, and a spammer tactic that would be better banned by ALL servers.

nilo.losbanos · 15-12-2004, 06:39

sorry i wasnt clear before. I was trying to send a test email from Bigfoot to an NTL email address. I am working for Bigfoot and I am testing our connection to NTL. What i did was the usual email test done on a telnet session. The error can only be seen during the test via telnet and in our log files but not as a bounce message.

The error doesnt say that it is due to a blacklist. It might be because of some recent updates in NTL's antispam service? I am hoping that somebody from NTL are monitoring this thread and give a comment.

sheka · 15-12-2004, 13:54

usually though if someone is sending an email to my bigfoot.com address the originator email would be something else.

If you telnet to smtp.ntlworld.com and try and send an email to a valid NTLworld account but with a non bigfoot.com originator address what happens?

I tried exactly what you did...yet my mail was accepted. If it is SPAM related then are NTL blocking the IP range for Bigfoot? Can you try from a non bigfoot registered IP address?

I have PM'd you as I have an open problem ticket with bigfoot re this problem. This has also been raised with NTl so with 2 groups working on this it should take less time to resolve.

nostra · 15-12-2004, 16:10

ntl have recently introduced spam filtering techniques involving blacklisting

so the best answer would be to resolve the issue with the blacklists that are blocking you, as there are most likely other hosts who would cause the same issues

sheka · 16-12-2004, 14:14

As I have had to put in place work arounds to get my email working when someone send email addressed to me at ......@bigfoot.com. I have access to more information.

Interestingly - when I send mail to my bigfoot.com address my mail system logs the following :

IP address 211.115.216.228 found in DNS blacklist SORBS DNSBL
IP address 211.115.216.225 found in DNS blacklist SORBS DNSBL

reverse DNS Lookups reveal:
211.115.216.228 PTR record: mail-kr.bigfoot.com
211.115.216.225 PTR record: mail-kr.bigfoot.com
A quick look on http://www.dnsbl.nl.sorbs.net/lookup.shtml brings up

Currently active and flagged to be published in DNS

It appears therefore that Bigfoot.com appears in a blacklist and NTL are just droppping the mail requests.