Access denied due to DNSBL

Why would you get a message like this "Denied access due to DNSBL listing." when trying to access a mail service?

Occurrence
It happens when I am using Digicel internet to access Telecom Vanuatu (TVL) webmail.

Equipment
EGDGE/GPRS USB Modem

Digicel internet is sourced from Fiji.

IP Address: 202.170.40.71

Carrier APN Settings
Source: http://modmyi.com/wiki/index.php/Carrier_APN_Settings


DIGICEL FIJI
Connection Settings(GPRS/EDGE)
Data Account Name WEB: Digicel
GPRS Access Point Name (APN): web.digicelpacific.com
PPP Authentication Type: Default
GPRS Username / Data Account: N/A
GPRS Password / Data Account: N/A
Private or Public?: Public
Primary DNS Server IP: Na
Secondary DNS Server IP: Na

Wap Settings Settings name – Digicel Wap
Session Mode – Permanent
Connection Security – Off
Data Bearer – GPRS
GPRS access point – wap.digicelpacific.com
IP address – 10.150.122.12
Authentication Type – Normal
Proxy Port – 8081
MMS Settings Settings Name – Digicel MMS
Homepage – .http://mms.digicelpacific.com:8990
Session Mode – Permanent
Data Bearer – GPRS
GPRS access point – wap.digicelpacific.com
IP address – 10.150.122.12
Authentication Type – Normal
Port - 808

Telecom Vanuatu Webmail
http://webmail.vanuatu.com.vu

What is a DNSBL?
Source: http://www.dnsbl.info/

Domain Name System Blacklists, also known as DNSBL's or DNS Blacklists, are spam blocking lists that allow a website administrator to block messages from specific systems that have a history of sending spam. As their name implies, the lists are based on the Internet's Domain Name System, which converts complicated, numerical IP address such as 140.239.191.10 into domain names like example.net, making the lists much easier to read, use, and search. If the maintainer of a DNS Blacklist has in the past received spam of any kind from a specific domain name, that server would be "blacklisted" and all messages sent from it would be either flagged or rejected from all sites that use that specific list.DNS Blacklists have a rather long history in web terms, with the first one being created in 1997. Called the RBL, its purpose was to block spam email and to educate Internet service providers and other websites about spam and its related problems. Although modern DNS Blacklists are rarely used as educational tools, their function as an email blocker and filter still serves as their primary purpose to this day. In fact, almost all of today's email servers support at least one DNSBL in order to reduce the amount of junk mail clients using their service receive. The three basic components that make up a DNS Blacklist - a domain name to host it under, a server to host that domain, and a list of addresses to publish to the list - also haven't changed from the time when the RBL was first created to today.Since then, dozens of different DNSBL's have sprung up and are available for use, and they all have their own lists that are populated based on what does or doesn't meet their own standards and criteria for what a spammer is. Because of this, DNS Blacklists can vary greatly from one to the other. Some are stricter than others, some only list sites for a set amount of time from the date the last piece of spam was received by the maintainer versus others that are manually maintained, and still others not only block IP addresses, but also entire ISP's known to harbor spammers. This results in some lists working better than others because they are maintained by services with a greater level of trustworthiness and credibility than competing lists might have. Users can also use these differences to decide on which DNS Blacklist works best for them depending on what their specific security needs are. Less lenient lists might allow more spam to get through, but might not block non-spam messages that have been misidentified on lists that have stricter guidelines for what goes on or what is left off of it. To help facilitate this, DNS Blacklists that are intended for use by the public will usually have a specific, published policy detailing what a listing means and must adhere to the criteria laid out in it in order to not only attain public confidence in their services, but to sustain it as well.Webmail services or Internet Service Providers use certain DNSBL service on their network.Some of these DNSL have blacklisted 202.170.40.71.In order to solve the problem, the IP address needs to removed from the block list.

Tested 202.170.40.71 with DNSBL.info Quick DNSBL Check

Results:81
Total 8 Listed

Conclusion

Webmail services or mail poviders use certain DNSBL service to reduce junk and spam mails.

TVL mail DNSBL provider have listed 202.170.40.71 and the IP address needs to be removed from the black list in order for webmail to be accessible.

The IP is Fiji Fintel's and it is listed in some DNSBL databases (www.dnsbl.info).

I posted a note on AVONSYS website with this questions, "how can it be corrected and who is responsible?".

Here's Franck Martin's response:

Contact FINTEL, it is their problem and contact telecom-vu webmail, they should not use DNSBL to block access to websites. All DNSBL lists are saying this is just plain wrong to do that!

So I need to know why TVL is using DNSBL in webmail, so i send a short note to my ISP and here's a response from my ISP.

The DNSBL is the process to identify IP that sending SPAM and black list those IP which is blocking some service as webmail.

We do not control that process but you can ask the person concern to clean up is PC (Scan for anti virus) and it will be release automatically from the black list controlled by SPAMHAUS.

The IP i got was assigned by Digicel Vanuatu and it is not a fixed IP.

Top 5 Digicel GPRS USB modem Advantages Vs Disadvantages

Advantages	Disadvantages	Solutions
Connect at any location where there is Digicel signal	Incompatible with Windows 7.	Solution for windows 7: Copy or download drivers and installation setup from windows xp and install in windows 7. Plug in USB modem and reboot machine Reboot several times if not working. Digicel should launch update soon.
Wireless connection. Easy to carry around and connect at any computer.	Error connecting to webmail.vanuatu.com.vu
Quick and easy way to text and mass text messaging via computer e.g. Cut and Paste	Bundle data too small and bigger bundles too expensive compared to ADSL.

Digicel Digimodem Mobile Tests

18 February 2010
By Matt Temar & Samson Busai

Our objective is to produce data for anyone interested in utilizing the Digimodem. The Digimodem can be useful for tracking systems.

Ouir test equipments:

Hardware

Laptop Notebook - Windows XP
Digimodem (USB) from Digicel
Blackberry Phone
Toyota Bus - Sam's (B 11064) Avg Speed 40km/hr

Software

Windows XP
Digicel application wizard installed.
Facebook Chat
Gmail Chat
DOS command - ping www.google.com -t

Testing real time connection by using chat and ping.

Results

Executing ping command to www.google.com -t.
Time-out as usual with the modem but applications are steady at number 3.
Latency very high in town maybe because of buildings.

Long time-out riding from Unelco to fungkuei

Connection established at Fatumaru Bay.

Long time-out from Tebakor Agriculture Supplies to Tebakor station.

Reply from 66.249.89.147: bytes=32 time=1058ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.147: bytes=32 time=2021ms TTL=48
Good connection from Tebakor/Malapoa road to Solwota Club. Low latency.

Ping response
Reply from 66.249.89.147: bytes=32 time=956ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=915ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=872ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=948ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=925ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=943ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=961ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=920ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=920ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=957ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=915ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=951ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=951ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=925ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=942ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=981ms TTL=48<br /> Reply from 66.249.89.147: bytes=32 time=1306ms TTL=48<br /> <br /> Long time out from Tagabe to Mele.<br /> <br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1525ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=4427ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.
Mele connection not steady

Reply from 66.249.89.99: bytes=32 time=2362ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2795ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=2139ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=857ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=875ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=876ms TTL=48<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1108ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=874ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=873ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=873ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=969ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=866ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=886ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=882ms TTL=48
Mele-Maat road
Trac
Ping response
Reply from 66.249.89.99: bytes=32 time=2134ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1596ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=921ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2657ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2621ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=939ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3082ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=957ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2057ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2117ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3598ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1296ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2678ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2038ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3879ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=935ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2260ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2855ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3260ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2533ms TTL=48
Clems Hill

Ping response
Reply from 66.249.89.99: bytes=32 time=900ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=918ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=937ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=914ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=890ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=909ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=925ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=925ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=944ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2659ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1663ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=909ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=925ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=908ms TTL=48
Towards Tamate Village

Ping response
Reply from 66.249.89.99: bytes=32 time=886ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3337ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2236ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=3472ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1798ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.Reply from 66.249.89.99: bytes=32 time=923ms TTL=48
Up the hill towards Tamate village

Ping response
Reply from 66.249.89.99: bytes=32 time=2878ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2716ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1935ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1412ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=996ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=976ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=971ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=951ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=945ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1203ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1059ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=939ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2973ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=918ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=918ms TTL=48Request timed out.
Around Tamate Village

Ping response
Reply from 66.249.89.99: bytes=32 time=2973ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1952ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=921ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1021ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1057ms TTL=48<br /> Request timed out.
Long time-out from junction at Mangaliliu to Tanoliu

Stop at Tanoliu Village. FB chat not steady.

Message: Could not connect to Facebook Chat at this time.
tanoliu now 7:14pm Matt Sending: test 7:16pm Matt test

Ping response
Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=4331ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3644ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=963ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=937ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3482ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=2719ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3550ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3284ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3121ms TTL=48<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1632ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3901ms TTL=48<br /> Request timed out.<br /> Request timed out.
We captured some changes on our return trip. Between Mangaliliu road and Tanoliu, we had some ping responses. We concluded that, our connection depends on the Digicel tower locations.

Ping responses
Request timed out.<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=1419ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1439ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3178ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Reply from 66.249.89.99: bytes=32 time=4163ms TTL=48<br /> Request timed out.<br /> Request timed out.<br /> Request timed out.
At Tamate Village, the connection is better than before. There is a tower right next to the village.

Ping response
Reply from 66.249.89.99: bytes=32 time=940ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=920ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=937ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=912ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=912ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=989ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=965ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=924ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=924ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=919ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=937ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=936ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=913ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=911ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1013ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=913ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=932ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=946ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=1299ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=3599ms TTL=48<br /> Reply from 66.249.89.99: bytes=32 time=2480ms TTL=48