HowtoForge Forums | HowtoForge - Linux Howtos and Tutorials - Captcha System Solution for the SPAM problem

HowtoForge Forums | HowtoForge - Linux Howtos and Tutorials (http://www.howtoforge.com/forums/index.php)

- Installation/Configuration (http://www.howtoforge.com/forums/forumdisplay.php?f=16)

- - Captcha System Solution for the SPAM problem (http://www.howtoforge.com/forums/showthread.php?t=23605)

Captcha System Solution for the SPAM problem

Hi Guys,

I need to know if is possible create a simple web interface with Black List - White List and Captcha authentication for the users to avoid the Spam problem.

Thanks

In my opinion, these systems are completely unusable. Users will not be able to do things like online shopping, mailing lists, forum registartions and many other things which require a double opt in anymore.

Instead of using such a system, you should setup a well maintained spamassassin integrated with amavisd and DNS blacklists. I use such a system for my accounts, I get about 500 - 600 emails a day, about 80 - 90% of them is spam and just a single spam message every few days gets trough the filters.

The problem remains the same, write a simple and immediate guide stap by step for all people who need a perfect configuration.

Let me know something about your solution.

This is my local.cf

Code:

# This is the right place to customize your installation of SpamAssassin.

#

# See 'perldoc Mail::SpamAssassin::Conf' for details of what can be

# tweaked.

#

# Only a small subset of options are listed below

#

###########################################################################



#   Add *****SPAM***** to the Subject header of spam e-mails

#

# rewrite_header Subject *****SPAM*****





#   Save spam messages as a message/rfc822 MIME attachment instead of

#   modifying the original message (0: off, 2: use text/plain instead)

#

# report_safe 1





#   Set which networks or hosts are considered 'trusted' by your mail

#   server (i.e. not spammers)

#

# trusted_networks 212.17.35.





#   Set file-locking method (flock is not safe over NFS, but is faster)

#

# lock_method flock





#   Set the threshold at which a message is considered spam (default: 5.0)

#

# required_score 5.0





#   Use Bayesian classifier (default: 1)

#

# use_bayes 1





#   Bayesian classifier auto-learning (default: 1)

#

# bayes_auto_learn 1





#   Set headers which may provide inappropriate cues to the Bayesian

#   classifier

#

# bayes_ignore_header X-Bogosity

# bayes_ignore_header X-Spam-Flag

# bayes_ignore_header X-Spam-Status

well maintained spamassassin integrated with amavisd and DNS blacklists

Is there a guide on how to setup well maintained spamassassin integrated with amavisd and DNS blacklists. Please advise?

Quote:

Originally Posted by till (Post 127578)

Instead of using such a system, you should setup a well maintained spamassassin integrated with amavisd and DNS blacklists. I use such a system for my accounts, I get about 500 - 600 emails a day, about 80 - 90% of them is spam and just a single spam message every few days gets trough the filters.

Basically a setup like this should work well:

http://www.howtoforge.com/virtual-us...ail-ubuntu8.04

combined with these additional postfix settings:

http://www.howtoforge.com/block_spam..._level_postfix

You can use this setup e.g. as dedicated spam server in front of your normal mailservers by forwarding the emails after the scanning process with postfix transports.

Another way is to use ispconfig 3

http://www.howtoforge.com/forums/showthread.php?t=22788

as it sets up the virtual server setup automatically during installation and offers a easy to use interface and the ability to maintain different antispam scorings and per domain or even per email address, you will just have to add razor, pyzor, dcc and the blacklists as described in the howtos above.

I already have server with ISPConfig Version: 2.2.23 with 10 domains and I've already did a setup from link below, somehow many emails still get lots of SPAM.

http://www.howtoforge.com/block_spam..._level_postfix

What other approach I can take to block the SPAM on already installed CentOS 5.1 with ISPConfig 2.2.23?

Install razor, pyzor and dcc. spamassassin will use them automatically, when they are installed.

I found how to install razor, pyzor and dcc (link below) but this is with amavisd which I don't think I have. Do I need amavisd? How do I install razor, pyzor and dcc w/o amavisd?

http://www.howtoforge.com/virtual-us...l-centos5.1-p4

Quote:

Do I need amavisd? How do I install razor, pyzor and dcc w/o amavisd?

you dont need amavisd. The installation with and without amavisd is the same.

Quote:

Do I need amavisd? How do I install razor, pyzor and dcc w/o amavisd?

you dont need amavisd. The installation with and without amavisd is the same.