Quick and dirty example of how to interface with SpamAssassin using sockets in PHP.

gistfile1.txt

<?php
/*
Copyright 2013 Andrew Rose http://andrewrose.co.uk
*/

class spamc
{
	private static $version = 'SPAMC/1.2';
	
	public static function test($email, $cmd='CHECK', $user='default', $ip='127.0.0.1', $port=783)
	{
		$sock = stream_socket_client('tcp://'.$ip.':'.$port, $errno, $errstr, 30);
		if (!$sock)
		{
			echo "Failed to connect to spamd, is spamassassin* running?\n";
			return FALSE;
		}
	
		$packet  = $cmd.' '.self::$version."\n";
		$packet .= 'Content-length: '.(strlen($email)+1)."\n";
		$packet .= 'User: '.$user."\n\r\n";
	
		fwrite($sock, $packet.$email."\n");
		$resp = fread($sock, 256000);
	
		switch($cmd)
		{
			/*
			SPAMD/1.1 0 EX_OK
			Spam: True ; 7.9 / 5.0
			*/
			case 'CHECK':
			{
				return trim(explode(':', explode(';', explode("\n", $resp)[1])[0])[1])=='True'?TRUE:FALSE;
			}
			break;
		}
	}
}

if(spamc::test('<raw email content here'))
{
	echo "Spam!\n";
}
else
{
	echo "Not Spam!\n";
}