SpamAssassin
What is spamassassin ?
———————-
The SpamAssassin system is software for analyzing email messages,
determining how likely they are to be spam, and reporting its conclusions.
It is a rule-based system that compares different parts of email messages
with a large set of rules. A message with a high enough score is reported to
be spam.
How it works ? : -
—————
–> There are several ways that SpamAssassin makes up its mind about a
message:
–> The message headers can be checked for consistency and adherence to
Internet standards (e.g., is the date formatted properly?).
–> The headers and body can be checked for phrases or message elements
commonly found in spam (e.g., “MAKE MONEY FAST” or instructions on how to be
removed from future mailings)-in several languages.
–> The headers and body can be looked up in several online databases that
track message checksums of verified spam messages.
–> The sending system’s IP address can be looked up in several online lists
of sites that have been used by spammers or are otherwise suspicious.
–> Specific addresses, hosts, or domains can be blacklisted or whitelisted.
A whitelist can be automatically constructed based on the sender’s past
history of messages.
–> SpamAssassin can be trained to recognize the types of spam that you
receive by learning from a set of messages that you consider spam and a set
that you consider non-spam. (SpamAssassin and the spam-filtering community
often refer to non-spam messages as ham. )
–> The sending system’s IP address can be compared to the sender’s domain
name using the Sender Policy Framework (SPF) protocol (http://spf.pobox.com)
to determine if that system is permitted to send messages from users at that
domain. This feature requires SpamAssassin 3.0.
–> SpamAssassin can privilege senders who are willing to expend some extra
computational power in the form of Hashcash (http://www.hashcash.org).
Spammers cannot do these computations and still send out huge amounts of
mail rapidly. This feature requires SpamAssassin 3.0.
Most of SpamAssassin’s behavior is controlled through a systemwide
configuration file and a set of per-user configuration files. The per-user
configuration can also be stored in an SQL database.
How to Configure it ? : -
——————-
You can easily customize how SpamAssassin tags and identifies spam by
creating a spamassassin/user_prefs file. You can customize the number of
“spam points” required to identify a message as spam, create new rules, and
re-weight existing rules. Here is a sample user_prefs file. It raises the
threshold for identifying spam from 5 to 6, disables including spam warnings
in the subject and body, reweights a known rule, and adds several blacklist,
whitelist, and header rules.
Listing 1. A typical user_prefs configuration file
================================================================
#How many hits before a mail is considered spam?
required_hits 6
#Don’t mangle the messages so badly
rewrite_subject 0
use_terse_report 1
#whitelist and blacklist
whitelist_from *@www.eukhost.com
blacklist_from annoying-person@xyz.com
#reweight an existing rule
score BASE64_ENC_TEXT 3
#add some new rules
header KNOWN_LIST List-Id =~ /a-mailing-list-i-like/
score KNOWN_LIST -3
body EVITE /This invitation was sent to you by .* using Evite/
describe EVITE Looks like an eVite
score EVITE -3
================================================================
At heart, SpamAssassin is a set of modules written in the Perl programming
language, along with a Perl script that accepts a message on standard input
and checks it using the modules. For higher-performance applications,
SpamAssassin also includes a daemonized version of the spam-checker and a
client program in C that can accept a message on standard input and check it
with the daemon.
Edward said,
September 29, 2006 @ 9:20 am
Yeah its totally configurable; I like the ability of setting rules that you can be able to select which rules you want to use.
web hosting said,
September 30, 2006 @ 2:16 am
Hey.. nice post. Especially the user_prefs file helps me a lot. Thanks for sharing this.
hosting uk said,
September 30, 2006 @ 2:17 am
Hey.. nice post. Especially the user_prefs file helps me a lot. Thanks for sharing this .
web hosting said,
October 18, 2006 @ 12:37 am
[...] –> There are several ways that SpamAssassin makes up its mind about a message: –> The message headers can be checked for consistency and adherence to Internet standards (e.g., is the date formatted properly?). –> The headers and body can be checked for phrases or message elements commonly found in spam (e.g., “MAKE MONEY FAST” or instructions on how to be removed from future mailings)-in several languages. –> The headers and body can be looked up in several online databases that track message checksums of verified spam messages. –> The sending system’s IP address can be looked up in several online lists of sites that have been used by spammers or are otherwise suspicious. –> Specific addresses, hosts, or domains can be blacklisted or whitelisted. A whitelist can be automatically constructed based on the sender’s past history of messages. –> SpamAssassin can be trained to recognize the types of spam that you receive by learning from a set of messages that you consider spam and a set that you consider non-spam. (SpamAssassin and the spam-filtering community often refer to non-spam messages as ham. ) –> The sending system’s IP address can be compared to the sender’s domain name using the Sender Policy Framework (SPF) protocol (http://spf.pobox.com) to determine if that system is permitted to send messages from users at that domain. This feature requires SpamAssassin 3.0. –> SpamAssassin can privilege senders who are willing to expend some extra computational power in the form of Hashcash (http://www.hashcash.org). Spammers cannot do these computations and still send out huge amounts of mail rapidly. This feature requires SpamAssassin 3.0. [...]
uk servers said,
October 18, 2006 @ 12:39 am
[...] What is Spam Assassin? The SpamAssassin system is software for analyzing email messages, determining how likely they are to be spam, and reporting its conclusions. It is a rule-based system that compares different parts of email messages with a large set of rules. Each rule adds or removes points from a message’s spam score. A message with a high enough score is reported to be spam. Spam Assassin is a e-mail spam filtering system that sits side by side with account with us to help block, mark or filter out mail you don’t want. [...]
» Mail failure due to spamd | Web Hosting Tutorials | Web Hosting Service | Linux Hosting said,
October 21, 2006 @ 7:51 pm
[...] 1.Go to WHM >> Tweak settings & disable Spamassassin 2.Go to Service Manager & disable spamd 3. # service exim restart [...]
Corporate website hosting said,
October 31, 2006 @ 2:12 pm
Spamassassin is an e-mail spam filtering system that sits side by side with account with us to help block, mark or filter out mail you don’t want. It can be activated from Cpanel, under the “Mail” box section.
Ann Hoff said,
November 9, 2006 @ 10:05 am
Using Captchas can minimize in certain level the computer generated spamming.
Outsourcing Hosting Support said,
November 10, 2006 @ 8:57 am
I would suggest to use spam assassin with a gpl OCR plugin.
Bob said,
November 13, 2006 @ 10:06 am
Spamassain help it configured properly, however I think it should constantly tweaked with new rules to catch ever evolving spam as spammer are smart enough.
» How spamassassin works. | WebHosting UK Tutorials | Web Hosting UK said,
November 27, 2006 @ 1:28 pm
[...] –> There are several ways that SpamAssassin makes up its mind about a message: –> The message headers can be checked for consistency and adherence to Internet standards (e.g., is the date formatted properly?). –> The headers and body can be checked for phrases or message elements commonly found in spam (e.g., “MAKE MONEY FAST” or instructions on how to be removed from future mailings)-in several languages. –> The headers and body can be looked up in several online databases that track message checksums of verified spam messages. –> The sending system’s IP address can be looked up in several online lists of sites that have been used by spammers or are otherwise suspicious. –> Specific addresses, hosts, or domains can be blacklisted or whitelisted. A whitelist can be automatically constructed based on the sender’s past history of messages. –> SpamAssassin can be trained to recognize the types of spam that you receive by learning from a set of messages that you consider spam and a set that you consider non-spam. (SpamAssassin and the spam-filtering community often refer to non-spam messages as ham. ) –> The sending system’s IP address can be compared to the sender’s domain name using the Sender Policy Framework (SPF) protocol (http://spf.pobox.com) to determine if that system is permitted to send messages from users at that domain. This feature requires SpamAssassin 3.0. –> SpamAssassin can privilege senders who are willing to expend some extra computational power in the form of Hashcash (http://www.hashcash.org). Spammers cannot do these computations and still send out huge amounts of mail rapidly. This feature requires SpamAssassin 3.0. [...]
Web Hosting Services » What is Spam Assassin and How it is work ? said,
December 26, 2006 @ 11:30 pm
[...] What is Spam Assassin? The SpamAssassin system is software for analyzing email messages, determining how likely they are to be spam, and reporting its conclusions. It is a rule-based system that compares different parts of email messages with a large set of rules. Each rule adds or removes points from a message’s spam score. A message with a high enough score is reported to be spam. Spam Assassin is a e-mail spam filtering system that sits side by side with account with us to help block, mark or filter out mail you don’t want. [...]
Web Hosting Reviews said,
December 29, 2006 @ 6:18 pm
SpamAssassin wins ‘Best Linux-based Anti-spam Solution’ at the Linux New Media Awards 2006, winning 69% of the vote . More details at http://spamassassin.apache.org/ .