Configuring a server to parse email via a PHP script

In this tutorial I'll show how you can setup a server to parse email with a PHP script. This tutorial assumes that your server is configured to receive email (I wrote this using a virtual machine running postfix).

The first thing you'll need to do is configure an alias to direct email to a PHP script (instead of an email box). I added the following entry to the bottom of my /etc/aliases file and then ran the "newaliases" command to refresh my aliases database:

phpscript: "|php -q /usr/local/bin/email.php"

The above entry will pipe email sent to phpscript@MYDOMAIN to the designated PHP script.

And here's the script:

#!/usr/bin/php
<?php

// fetch data from stdin
$data = file_get_contents("php://stdin");

// extract the body
// NOTE: a properly formatted email's first empty line defines the separation between the headers and the message body
list($data, $body) = explode("\n\n", $data, 2);

// explode on new line
$data = explode("\n", $data);

// define a variable map of known headers
$patterns = array(
  'Return-Path',
  'X-Original-To',
  'Delivered-To',
  'Received',
  'To',
  'Message-Id',
  'Date',
  'From',
  'Subject',
);

// define a variable to hold parsed headers
$headers = array();

// loop through data
foreach ($data as $data_line) {

  // for each line, assume a match does not exist yet
  $pattern_match_exists = false;

  // check for lines that start with white space
  // NOTE: if a line starts with a white space, it signifies a continuation of the previous header
  if ((substr($data_line,0,1)==' ' || substr($data_line,0,1)=="\t") && $last_match) {

    // append to last header
    $headers[$last_match][] = $data_line;
    continue;

  }

  // loop through patterns
  foreach ($patterns as $key => $pattern) {

    // create preg regex
    $preg_pattern = '/^' . $pattern .': (.*)$/';

    // execute preg
    preg_match($preg_pattern, $data_line, $matches);

    // check if preg matches exist
    if (count($matches)) { 

      $headers[$pattern][] = $matches[1];
      $pattern_match_exists = true;
      $last_match = $pattern;

    }

  }

  // check if a pattern did not match for this line
  if (!$pattern_match_exists) {
    $headers['UNMATCHED'][] = $data_line;
  }

}

?>

At this point in the code, the body of the message will be contained in the $body variable and the headers will be in $headers.

Here is an example of the parsed headers (using print_r()):

Array
(
    [UNMATCHED] => Array
        (
            [0] => From root@Eric-Centos.localdomain  Sun Jan 10 21:49:50 2010
        )

    [Return-Path] => Array
        (
            [0] => <root@Eric-Centos.localdomain>
        )

    [X-Original-To] => Array
        (
            [0] => phpscript
        )

    [Delivered-To] => Array
        (
            [0] => phpscript@Eric-Centos.localdomain
        )

    [Received] => Array
        (
            [0] => by Eric-Centos.localdomain (Postfix, from userid 0)
            [1] => 	id 4D03F30131; Sun, 10 Jan 2010 21:49:50 -0500 (EST)
        )

    [To] => Array
        (
            [0] => phpscript@Eric-Centos.localdomain
        )

    [Subject] => Array
        (
            [0] => This is the subject
        )

    [Message-Id] => Array
        (
            [0] => <20100111024950.4D03F30131@Eric-Centos.localdomain>
        )

    [Date] => Array
        (
            [0] => Sun, 10 Jan 2010 21:49:50 -0500 (EST)
        )

    [From] => Array
        (
            [0] => root@Eric-Centos.localdomain (root)
        )

)

Now, you have all the email headers and message body parsed. You can do whatever your heart desires with the data, like insert it into a database or even create nodes!

Kudryashovda

Submitted by Anonymous on Thu, 06/10/2010 - 08:59.

Thank's for manual

Very Clever little piece of script

Submitted by Anonymous on Mon, 06/07/2010 - 22:41.

Just a lil enhancement, instead of checking for blank space at the beginning of each line to see if it is a continuation of the previous line you can rather perform a simple "unfolding" technique.

According to http://www.faqs.org/rfcs/rfc2822.html
"Unfolding is accomplished by simply removing any CRLF
that is immediately followed by WSP. Each header field should be
treated in its unfolded form for further syntactic and semantic
evaluation."

Place this right above "// explode on new line"

$data= preg_replace('/\r\n\s/i', "", $data); // More correct
or
$data= preg_replace('/\n\s/i', "", $data); // Will also work

insertion into data base

Submitted by Anonymous on Wed, 04/21/2010 - 09:26.

Hello Eric

Thanks for yours infrmations, do you have some codes for injecting data into mysql ? :)
by using serialize($headers) ?

How to get attachment

Submitted by Anonymous on Fri, 01/07/2011 - 07:52.

Hi Eric

How i can get attachment and save into disk with your script?

--Umar