How to filter spam with Spamassassin and Postfix in Debian June 30, 2008

Install Spamassassin in Debian

#apt-get install spamassassin spamc

spamassassin package can also be integrated into a Mail Transport Agent such as postfix.

Preparation

By default Spamassassin will run as root users when you install from debian repository and is not started to avoid that, we are going to create a specific user and group for spamassassin.

#groupadd -g 5001 spamd

#useradd -u 5001 -g spamd -s /sbin/nologin -d /var/lib/spamassassin spamd

#mkdir /var/lib/spamassassin

#chown spamd:spamd /var/lib/spamassassin

we need to change some settings in /etc/default/spamassassin and make sure you get the following values

ENABLED=1
SAHOME=”/var/lib/spamassassin/”
OPTIONS="--create-prefs --max-children 5 --username spamd --helper-home-dir ${SAHOME} -s ${SAHOME}spamd.log"
PIDFILE=”${SAHOME}spamd.pid”

We are going to run spamd daemon as user spamd and make it use its own home dir (/var/lib/spamassassin/) and is going to output its logs in /var/lib/spamassassin/spamd.log

spamassassin Configuration

we need to give spamassassin some rules. The default settings are quite fine, but you might tweak them up a bit. So let’s edit /etc/spamassassin/local.cf and make it looks like that

#vi /etc/spamassassin/local.cf

Modify this file looks like below

rewrite_header Subject [***** SPAM _SCORE_ *****]
required_score 2.0
#to be able to use _SCORE_ we need report_safe set to 0
#If this option is set to 0, incoming spam is only modified by adding some “X-Spam-” headers and no changes will be made to the body.
report_safe 0

# Enable the Bayes system
use_bayes 1
use_bayes_rules 1
# Enable Bayes auto-learning
bayes_auto_learn 1

# Enable or disable network checks
skip_rbl_checks 0
use_razor2 0
use_dcc 0
use_pyzor 0

we set spamassassin’ spamd default settings to rewrite email subject to [***** SPAM _SCORE_ *****], where _SCORE_ is the score attributed to the email by spamassassin after running different tests, only if the actual score is greater or equal to 2.0. So email with a score lower than 2 won’t be modified.

To be able to use the _SCORE_ in the rewrite_header directive, we need to set report_safe to 0.

In the next section, we tell spamassassin to use bayes classifier and to improve itself by auto-learning from the messages it will analyse.

In the last section, we disable collaborative network such as pyzor, razor2 and dcc. Those collaborative network keep an up-to-date catalogue of know mail checksum to be recognized as spam. Those might be interresting to use, but I’m not going to use them here as I found it took long enough to spamassassin to deal with spams only using it rules.

Restart spamassassin using the following command

#/etc/init.d/spamassassin start

Configuring Postfix call Spamassassin

spamassassin will be invoked only once postfix has finished with the email.

To tell postfix to use spamassassin, we are going to edit /etc/postfix/master.cf

#vi /etc/postfix/master.cf

Change the following line

smtp inet n – – – – smtpd

to

smtp inet n – – – – smtpd
-o content_filter=spamassassin

and then, at the end of master.cf file add the following lines

spamassassin unix – n n – – pipe

user=spamd argv=/usr/bin/spamc -f -e
/usr/sbin/sendmail -oi -f ${sender} ${recipient}

Save and exit the file

That’s it our spam filter is setted up, we need to reload postfix settings and everything should be ready.

#/etc/init.d/postfix reload

Send emails using PHPMailer and GMail January 7, 2008

Sending emails using PHPMailer_v5.0.2 and GMail

Requirements :

1 : PHPMailer source code
2 : GMail account

Download the PHPMailer source code from http://sourceforge.net/project/showfiles.php?group_id=26031&package_id=252700

Now create a file you call mail.php on your harddisk and open it with your favorite text editor. Paste this code into it :

<?php

//error_reporting(E_ALL);
error_reporting(E_STRICT);

date_default_timezone_set('America/Toronto');

require_once('../class.phpmailer.php');
//include("class.smtp.php"); // optional, gets called from within class.phpmailer.php if not already loaded

$mail             = new PHPMailer();

$body             = file_get_contents('contents.html');
$body             = eregi_replace("[\]",'',$body);

$mail->IsSMTP(); // telling the class to use SMTP
$mail->Host       = "mail.yourdomain.com"; // SMTP server
$mail->SMTPDebug  = 2;                     // enables SMTP debug information (for testing)
 // 1 = errors and messages
 // 2 = messages only
$mail->SMTPAuth   = true;                  // enable SMTP authentication
$mail->SMTPSecure = "ssl";                 // sets the prefix to the servier
$mail->Host       = "smtp.gmail.com";      // sets GMAIL as the SMTP server
$mail->Port       = 465;                   // set the SMTP port for the GMAIL server
$mail->Username   = "yourusername@gmail.com";  // GMAIL username
$mail->Password   = "yourpassword";            // GMAIL password

$mail->SetFrom('name@yourdomain.com', 'First Last');

$mail->AddReplyTo("name@yourdomain.com","First Last");

$mail->Subject    = "PHPMailer Test Subject via smtp (Gmail), basic";

$mail->AltBody    = "To view the message, please use an HTML compatible email viewer!"; // optional, comment out and test

$mail->MsgHTML($body);

$address = "whoto@otherdomain.com";
$mail->AddAddress($address, "John Doe");

$mail->AddAttachment("images/phpmailer.gif");      // attachment
$mail->AddAttachment("images/phpmailer_mini.gif"); // attachment

if(!$mail->Send()) {
 echo "Mailer Error: " . $mail->ErrorInfo;
} else {
 echo "Message sent!";
}

?>