Spam Reduction 

Keep Your Inbox Clean 

Things You Should Know Before Using DNS Block Lists

DNS block lists are easy to include into most mail servers. They are a very effective and efficient server side tool to help keeping spam out of your systems. As the name implies they use domain name servers to transmit the information whether mails from a distinct mail server should be accepted or rejected.

 

Sometimes they are too effective. It can happen that a mail server is listed on a block list wrongfully. This can lead to a situation where your mail server will reject mails that you wanted to receive. The biggest problem with block lists is that you have to trust somebody else to take the right decision which mails to accept and which ones to reject.

So how useful are DNS block lists after evaluating the pros and cons? They can be very useful to lower the overall CPU usage of your anti spam strategy. It is advisable to use a small number of carefully chosen blocklists. If you are using a block list, subscribe to the mailing list or newsletter of the organization who runs the block list. That way you will take note of any problems that the block list may have and you will be informed if it gets shut down. DNS blocklists should never be your only strategy against spam. They should be combined with other mechanisms to help keeping spam out of your inbox.

There are some things you should consider before implementing DNS block lists in your anti spam strategy. If you reject a connection from a mail server because it is listed in a block list, return a detailed error message. This enables the admin of a mail server that gets listed wrongfully to see why the mails get rejected and to act accordingly.

If your mail server software allows to select the order of different sender or client restrictions be sure to put DNS blacklists after SMTP authentication. This enables your co-workers (and your customers if you are in the ISP business) to send their mails even if they come from a dial-in IP address that is listed in a block list.

You should consider using DNS block lists for scoring instead of blocking if your mail server has enough resources (CPU, IO, traffic). That would mean to use the block lists in a program like spamassassin that gives points for different criteria of a message and considers it as spam if it surpasses a certain number of points. That way the chances for false positives are lower because a message is not rejected if the sending server is on a single block list only. The message will get rejected if there are other signs of spam.

Huge indexes of available DNS block lists can be found at www.moensted.dk/spam/ and www.declude.com.

Spam Videos

Loading...

Spam Tool News

New Free Anti Spam Blocker Tool: Webmasters and Bloggers Fight Back

Manchester, NH (PRWEB) December 9, 2008 -- http://www.SpamDisapppears.com has launched with a free anti spam blocker tool to help any webmaster protect their web sites from being violated by email...

Read more...


byteplant Offers Advanced Anti Spam Protection; NoSpamToday! Version 3 Provides Administrators More Tools to Fight the Effects of Spam on Network Systems

Portland, Ore and Neuendettelsau, Germany (PRWEB) April 24, 2007 -- byteplant today announced the immediate availability of a new tool in the fight against junk e-mail. NoSpamToday! Version 3 anti...

Read more...


Choosing an SEO Firm To Drive Traffic to Your Online Store - ZippyCart


ZippyCart

Choosing an SEO Firm To Drive Traffic to Your Online Store
ZippyCart
Most of the SEO firms that try to get your attention via email, are using a spam tool that grabs domain names and email addresses and then sends a ...

Read more...


"Countdown to UFC 117" preview show debuts Aug. 2 on Spike TV - MMAjunkie.com


MMAjunkie.com

"Countdown to UFC 117" preview show debuts Aug. 2 on Spike TV
MMAjunkie.com
RULES: No spam. No fighter bashing. No insulting other posters. No disruptive posts. Nothing "Not Safe for Work" or illegal, including links to illegal ...

and more »

Read more...


Automation, partnerships drive Webroot revamp - CNET (blog)


Automation, partnerships drive Webroot revamp
CNET (blog)
... incorporating antivirus tools, the Spy Sweeper engine, two-way firewall, spam and phishing guards, file storage and sharing from SugarSync, ...

and more »

Read more...


Home
Related Sites

Spam block
Spam stopper
Outlook express spam
Dns black lists
Spamkiller
Antispam
Free outlook express spam filter
Filtering spam
Black lists
Anti spam filter
Spam control
Abuse spam
Blog comment spam
Dns block list
Dns block lists


 
Anti-Spam Measures: Analysis and Design
Anti-Spam Measures: Analysis and Design
by Guido Schryen
Our Price: $56.20
Used from: $56.20

Anti-Spam Tool Kit
Anti-Spam Tool Kit
by Paul Wolfe Charlie Scott Mike Erwin
Used from: $0.40

Anti-Spam Legislation: Understanding the Implications for E-mail Marketers
Anti-Spam Legislation: Understanding the Implications for E-mail Marketers
by Jupiter Research Corporation
Our Price: $195.00
Used from: $195.00