Emails being blocked by NTL

[Tiko]

Thanks Toto. That does help a little and having found this forum I was beginning to pick up that much.

So ntl could say the emails will be discarded if they come from a server with an IP address on X or Y blocklists.

What I was getting at is why couldn't ntl make it easy to find out that they use block lists and tell us which ones so that we can check for ourselves if mail is likely to be missing. Up to now I only have the info on this forum to say this is what happens.
Can I accept your answer as the definitive and up to date list of blocklists used by ntl? and which of the various lists at Spamhaus, say, is it ntl uses ? Are you privy to ntl policy and practice on this issue ? With what authority ?

Spamhause own site says:
"We ask, but do not require, that all ISPs using the SBL and/or XBL inform customers of the fact you run spam filters (simply because it is the correct thing to do). Use of known-to-be-effective spam blocklists is normally seen as a service advantage and strong sales point. All SBL and XBL Users are welcome to use the email protected by SBL and XBL web badges on sites"

By giving the option of having some SPAM marked and directed to a particular mail folder and saying nothing of emails being rejected ntl gives the impression that no emails are being discarded even before that stage.

If emails coming from IPs on the spamhaus/spamcop lists are discarded outright before the end user gets the chance to see it, then which SPAM is marked and put under the end user control if that option is chosen ?


I must admit that although I can see arguments both ways the risk of losing good emails (and not even knowing about it) seems to outway the benefits of this method of fighting unwanted email and I want to know what the risk is before signing up for a package which includes email.

Any comment on the crass response from ntl to my enquiry ?
You, presumably not employed by ntl and paid to help their potential customers, have done more than their staff to give me info about their system. Quite honestly that response is enough to put me off them without even getting the info about their email handling.

I need to check out this Brightmail thing as well.

---------- Post added at 10:10 ---------- Previous post was at 10:01 ----------

Originally Posted by Toto

if you know the SMTP server of the sender, and check the IP address of that server against the links below, you may get a vlue.

Spamcop here
Spamhaus here

Hope that helps.

I understand that you were trying to be helpful - but ...

How would I know the SMTP server of the sender of an email I don't even know I haven't received because it has been completely silently discarded with no info to the sender or intended recipient?

[jackclare]

Originally Posted by Tiko

Thanks Toto. That does help a little and having found this forum I was beginning to pick up that much.

So ntl could say the emails will be discarded if they come from a server with an IP address on X or Y blocklists.

What I was getting at is why couldn't ntl make it easy to find out that they use block lists and tell us which ones so that we can check for ourselves if mail is likely to be missing. Up to now I only have the info on this forum to say this is what happens.
Can I accept your answer as the definitive and up to date list of blocklists used by ntl? and which of the various lists at Spamhaus, say, is it ntl uses ? Are you privy to ntl policy and practice on this issue ? With what authority ?

The last time I checked Spamhaus and spamcop did not show any block but uceprotect.net showed a level 3 block on 81.103.221.10. I am once again receiving emails from wanadoo so this seems to have been cleared although I have not checked whether the block has cleared. It would seem that uceprotect is the latest used by NTL.
Spamhause own site says:
"We ask, but do not require, that all ISPs using the SBL and/or XBL inform customers of the fact you run spam filters (simply because it is the correct thing to do). Use of known-to-be-effective spam blocklists is normally seen as a service advantage and strong sales point. All SBL and XBL Users are welcome to use the email protected by SBL and XBL web badges on sites"

By giving the option of having some SPAM marked and directed to a particular mail folder and saying nothing of emails being rejected ntl gives the impression that no emails are being discarded even before that stage.

If emails coming from IPs on the spamhaus/spamcop lists are discarded outright before the end user gets the chance to see it, then which SPAM is marked and put under the end user control if that option is chosen ?


I must admit that although I can see arguments both ways the risk of losing good emails (and not even knowing about it) seems to outway the benefits of this method of fighting unwanted email and I want to know what the risk is before signing up for a package which includes email.

Any comment on the crass response from ntl to my enquiry ?
You, presumably not employed by ntl and paid to help their potential customers, have done more than their staff to give me info about their system. Quite honestly that response is enough to put me off them without even getting the info about their email handling.

I need to check out this Brightmail thing as well.

---------- Post added at 10:10 ---------- Previous post was at 10:01 ----------



I understand that you were trying to be helpful - but ...

How would I know the SMTP server of the sender of an email I don't even know I haven't received because it has been completely silently discarded with no info to the sender or intended recipient?

---------- Post added at 12:16 ---------- Previous post was at 12:11 ----------

Seem to have made a mess of this reply. However , the last time I looked spamhaus and spamcop showed no block but uceprotect.net showed a level3 block on 81.103.221.10. Messages are now coming through but it looks as though this is another agent being used by NTL

[Toto]

Originally Posted by jackclare

---------- Post added at 12:16 ---------- Previous post was at 12:11 ----------

Seem to have made a mess of this reply. However , the last time I looked spamhaus and spamcop showed no block but uceprotect.net showed a level3 block on 81.103.221.10. Messages are now coming through but it looks as though this is another agent being used by NTL

Hmm.....that will hit ntl email users sending through ntl servers when the recipeint server uses that block list.

---------- Post added at 13:58 ---------- Previous post was at 13:50 ----------

Originally Posted by Tiko

Thanks Toto. That does help a little and having found this forum I was beginning to pick up that much.

So ntl could say the emails will be discarded if they come from a server with an IP address on X or Y blocklists.

What I was getting at is why couldn't ntl make it easy to find out that they use block lists and tell us which ones so that we can check for ourselves if mail is likely to be missing. Up to now I only have the info on this forum to say this is what happens.
Can I accept your answer as the definitive and up to date list of blocklists used by ntl? and which of the various lists at Spamhaus, say, is it ntl uses ? Are you privy to ntl policy and practice on this issue ? With what authority ?

Spamhause own site says:
"We ask, but do not require, that all ISPs using the SBL and/or XBL inform customers of the fact you run spam filters (simply because it is the correct thing to do). Use of known-to-be-effective spam blocklists is normally seen as a service advantage and strong sales point. All SBL and XBL Users are welcome to use the email protected by SBL and XBL web badges on sites"

By giving the option of having some SPAM marked and directed to a particular mail folder and saying nothing of emails being rejected ntl gives the impression that no emails are being discarded even before that stage.

If emails coming from IPs on the spamhaus/spamcop lists are discarded outright before the end user gets the chance to see it, then which SPAM is marked and put under the end user control if that option is chosen ?


I must admit that although I can see arguments both ways the risk of losing good emails (and not even knowing about it) seems to outway the benefits of this method of fighting unwanted email and I want to know what the risk is before signing up for a package which includes email.

Any comment on the crass response from ntl to my enquiry ?
You, presumably not employed by ntl and paid to help their potential customers, have done more than their staff to give me info about their system. Quite honestly that response is enough to put me off them without even getting the info about their email handling.

I need to check out this Brightmail thing as well.

---------- Post added at 10:10 ---------- Previous post was at 10:01 ----------



I understand that you were trying to be helpful - but ...

How would I know the SMTP server of the sender of an email I don't even know I haven't received because it has been completely silently discarded with no info to the sender or intended recipient?

OK, kind of left something out of my response.....sorry

Any network that is prevented from sending email at the first stage, block list check, their server receives an error message telling them that their server is on a block list, including a URL to reference their blocked status. That mail server admin team can then resolve the issue with the block list host.

So whilst the intended recipient of the email will not know that a mail sent to them has failed due to blocking, the sender of that email, or their network operator should.

Worth keeping in mind also is that the lists are dynamic, and many blocked networks become unblocked after a period of time, even if the network has not taken sufficient action in time to resolve the issue.

I think that ntl technical support chaps send out an email to a customer who has contacted them regarding a blocked email issue, the answer they give is probably better than mine as they will have better knowledge of the process.

Hope that helps.

[Tiko]

Toto
====
That is something - even if ordinary email users do not know how many emails are going undelivered our technical guardians do - but do they do anything about it?

I have yet to see any evidence that ntl technical support have any knowledge of the process (based on response or lack of to my enquiry)

I don't know about these lists being dynamic especially reading this bit on SORBS website
=================================

Please note that entries in the SORBS DUHL never expire, not even the entries we inherited from Easynet NL Dynablock. We always require contact from the network owner for modifications.
=================================

This relates to (for example)
Netblock: 82.1.32.0/19 (82.1.32.0-82.1.63.255)
Record Created: Thu Sep 16 13:37:21 2004 GMT
Record Updated: Thu Sep 16 13:37:21 2004 GMT
Additional Information: Dynamic/Generic IP/rDNS address, use your ISPs mail server or get rDNS set to indicate static assignment.
Currently active and flagged to be published in DNS

These are IPs allocated by ntl to their users on the SORBS list since 2004 if I am reading this correctly. (I know this is the other side of the coin - potential blocking of mail going out from ntl users but it makes the point.)

---------- Post added at 20:50 ---------- Previous post was at 20:42 ----------

jackclare
=======

You certainly did mess up that last message. In fact you "put words in my mouth" by inserting text in the middle of my quoted message - any chance that you could do the decent thing and edit it please?

[Toto]

Originally Posted by Tiko

Toto
====
That is something - even if ordinary email users do not know how many emails are going undelivered our technical guardians do - but do they do anything about it?

I have yet to see any evidence that ntl technical support have any knowledge of the process (based on response or lack of to my enquiry)

I don't know about these lists being dynamic especially reading this bit on SORBS website
=================================

Please note that entries in the SORBS DUHL never expire, not even the entries we inherited from Easynet NL Dynablock. We always require contact from the network owner for modifications.
=================================

This relates to (for example)
Netblock: 82.1.32.0/19 (82.1.32.0-82.1.63.255)
Record Created: Thu Sep 16 13:37:21 2004 GMT
Record Updated: Thu Sep 16 13:37:21 2004 GMT
Additional Information: Dynamic/Generic IP/rDNS address, use your ISPs mail server or get rDNS set to indicate static assignment.
Currently active and flagged to be published in DNS

These are IPs allocated by ntl to their users on the SORBS list since 2004 if I am reading this correctly. (I know this is the other side of the coin - potential blocking of mail going out from ntl users but it makes the point.)

---------- Post added at 20:50 ---------- Previous post was at 20:42 ----------

Ahh, ok, what you are refering to there is a list of IP addresses that are dynamically assigned, that list is a little different.

In a nut shell all IP's in that list should not be running their own mail server other than the mail server matching the MX record of the domain in question.

Those lists are built in conjunction with the ISP's to help networks to make decisions about whehter to accept emails from dynamic IP addresses that are running their own mail servers, something that is generally accepted should not be happening.

What does his mean in practice therefore for a dynamic ntl IP address?

If the source IP address is using a known ntl SMTP server, such as smtp.ntlworld.com, then the email will be passed for delivery, however, if it is not an ntl mail server, then the recipient server will reject the email if it uses the SORBS DUHL. I think that's a pretty basic explanation, if anybody more techy wants to chip in, please do.

The Block Lists are dynamic, and an explanation of the spamcop listing policy can be found here

Really hope that helps a little more.

[jackclare]

Originally Posted by Tiko

Toto
====
---------- Previous post was at 20:42 ----------

jackclare
=======

You certainly did mess up that last message. In fact you "put words in my mouth" by inserting text in the middle of my quoted message - any chance that you could do the decent thing and edit it please?

Apologies, not much good at finding my way round. Will try harder

[jdogsbody]

Originally Posted by Toto

So whilst the intended recipient of the email will not know that a mail sent to them has failed due to blocking, the sender of that email, or their network operator should.

.

I haven`t found out that mail hasn`t been delivered until 3 days after it`s been sent, which is a bit late to try to make contact any other way if the email is important/urgent!