In the functions directory of your SquirrelMail install, open the imap_general.php file.

Alter the sqimap_append PHP function by commenting out the line that starts with the fputs function and type in the replacement so it reads as:

function sqimap_append ($imap_stream, $sent_folder, $length) {
//    fputs ($imap_stream, sqimap_session_id() . " APPEND \"$sent_folder\" (\\Seen) \{$length}\r\n");
    fputs ($imap_stream, sqimap_session_id() . " APPEND \"$sent_folder\" (\\Seen) {" . $length . "}\r\n");
    $tmp = fgets ($imap_stream, 1024);
    sqimap_append_checkresponse($tmp, $sent_folder);
}

Save the changes and the problem should be solved. FYI: Upgrading to the latest version of SquirrelMail will resolve this issue as well, but applying this code change is less of a hassle.

Fix Source: XMail Forum -> dovecot imap cannot append

You can use these commands to force the upgrade.

pear upgrade --force http://pear.php.net/get/Archive_Tar http://pear.php.net/get/XML_Parser http://pear.php.net/get/Console_Getopt-1.2.2
pear upgrade --force http://pear.php.net/get/PEAR-1.3.3 (use only if your PEAR is older than v1.3.3)
pear upgrade --force http://pear.php.net/get/PEAR-1.4.3
pear upgrade PEAR

Here you can see the upgrade in action (fun fun fun).

[root@linux ~]# pear upgrade --force http://pear.php.net/get/Archive_Tar http://pear.php.net/get/XML_Parser http://pear.php.net/get/Console_Getopt-1.2.2
downloading Archive_Tar-1.3.2.tgz ...
Starting to download Archive_Tar-1.3.2.tgz (17,150 bytes)
......done: 17,150 bytes
WARNING: channel "pear.php.net" has updated its protocols, use "channel-update pear.php.net" to update
downloading XML_Parser-1.2.8.tgz ...
Starting to download XML_Parser-1.2.8.tgz (13,476 bytes)
...done: 13,476 bytes
downloading Console_Getopt-1.2.2.tgz ...
Starting to download Console_Getopt-1.2.2.tgz (4,252 bytes)
...done: 4,252 bytes
Did not download optional dependencies: pear/XML_RPC, use --alldeps to download automatically
warning: pear/PEAR dependency package "pear/Console_Getopt" downloaded version 1.2.2 is not the recommended version 1.2.3
downloading PEAR-1.7.1.tgz ...
Starting to download PEAR-1.7.1.tgz (302,377 bytes)
...done: 302,377 bytes
upgrade ok: channel://pear.php.net/PEAR-1.7.1
PEAR: Optional feature webinstaller available (PEAR's web-based installer)
PEAR: Optional feature gtkinstaller available (PEAR's PHP-GTK-based installer)
PEAR: Optional feature gtk2installer available (PEAR's PHP-GTK2-based installer)
upgrade ok: channel://pear.php.net/Console_Getopt-1.2.2
upgrade ok: channel://pear.php.net/XML_Parser-1.2.8
upgrade ok: channel://pear.php.net/Archive_Tar-1.3.2
To install use "pear install pear/PEAR#featurename"
[root@linux ~]# pear upgrade --force http://pear.php.net/get/PEAR-1.4.3
downloading PEAR-1.4.3.tgz ...
Starting to download PEAR-1.4.3.tgz (276,859 bytes)
.........................................................done: 276,859 bytes
WARNING: channel "pear.php.net" has updated its protocols, use "channel-update pear.php.net" to update
Did not download optional dependencies: pear/XML_RPC, use --alldeps to download automatically
downloading Console_Getopt-1.2.3.tgz ...
Starting to download Console_Getopt-1.2.3.tgz (4,011 bytes)
...done: 4,011 bytes
upgrade ok: channel://pear.php.net/Console_Getopt-1.2.3
upgrade ok: channel://pear.php.net/PEAR-1.4.3
PEAR: Optional feature webinstaller available (PEAR's web-based installer)
PEAR: Optional feature gtkinstaller available (PEAR's PHP-GTK-based installer)
PEAR: To install optional features use "pear install pear/PEAR#featurename"
[root@linux ~]# pear upgrade PEAR
WARNING: channel "pear.php.net" has updated its protocols, use "channel-update pear.php.net" to update
Did not download optional dependencies: pear/XML_RPC, use --alldeps to download automatically
downloading PEAR-1.7.1.tgz ...
Starting to download PEAR-1.7.1.tgz (302,377 bytes)
..............................................................done: 302,377 bytes
upgrade ok: channel://pear.php.net/PEAR-1.7.1
PEAR: Optional feature webinstaller available (PEAR's web-based installer)
PEAR: Optional feature gtkinstaller available (PEAR's PHP-GTK-based installer)
PEAR: Optional feature gtk2installer available (PEAR's PHP-GTK2-based installer)
To install use "pear install PEAR#featurename"

This article is based entirely from this PEAR Bug posting:
PEAR :: Bug #12990 :: Issues with PEAR Upgrade News Item from 1/3/08

This is the code to create the image. It returns an image resource identifier. Note the use of a custom TrueType font — you’ll need to change that line to the path of a font on your system.

<?php
// generate captcha image - returns image handle
function captcha_image($code_string, $img_width=150, $img_height=40) {
  // seed srand
  srand((double)microtime()*1000000);

  // create image
  $im = @imagecreate($img_width, $img_height) or die("Cannot Initialize new GD image stream");

  // security code
  $security_code = $code_string;

  // define font
  $font = "/usr/fonts/ttf/Georgia.ttf";

  // create some colors
  $black = imagecolorallocate($im, 0, 0, 0);
  $white = imagecolorallocate($im, 255, 255, 255);
  $grey = imagecolorallocate($im, 128, 128, 128);

  // randomness, we need lots of randomness 
  // background color -> 1=black, 2=white, 3=grey (more colors can be added)
  // lines -> black bg (1=white or 2=grey), white bg (1=black or 2=grey), grey bg (black only)
  $randval = rand(1, 3);
  if ($randval == 1) {
    $bgcolor = $black;
    $fontcolor = $white;
    $linecolor = ((rand(0, 1) == 0) ? $black : $white);
  } elseif ($randval == 2) {
    $bgcolor = $white;
    $fontcolor = $black;
    $linecolor = ((rand(0, 1) == 0) ? $black : $white);
  } else {
    $bgcolor = $grey;
    $fontcolor = $black;
    $linecolor = ((rand(0, 1) == 0) ? $black : $grey);
  }

  // line positioning and increment
  $x_start = rand(0, 10);
  $x_size = rand(5, 10);
  $y_start = rand(0, 10);
  $y_size = rand(5, 10);

  // fill with background color
  imagefill($im, 0, 0, $bgcolor);

  // initial x position
  $font_x = 10;

  // write text
  for ($i = 0; $i < strlen($security_code); $i++) {
    // font size -> 20 to 35
    $font_size = rand(25, 35);
    // font angle -> -20 to +20
    $font_angle = rand(0, 20);
    if ($font_angle != 0) { if (rand(0, 1) == 0) { $font_angle = -$fone_angle; } }
    // font y position -> if font_size <= 27 then 30 to 35, if font_size > 27 then 30 to 35
    if ($font_size <= 27) { $font_y = rand(25, 30); } else { $font_y = rand(30, 35); }
    // write the text
    imagettftext($im, $font_size, $font_angle, $font_x, $font_y, $fontcolor, $font, $security_code{$i});
    // one more time to make it bolder
    imagettftext($im, $font_size, $font_angle, $font_x+1, $font_y+1, $fontcolor, $font, $security_code{$i});
    // next font x position
    $font_x += ($font_size + 5);
  }

  // draw horizontal lines
  for ($y = $y_start; $y < $img_height; $y += $y_size) {
    imageline($im, 0, $y, $img_width, $y, $linecolor);
  }
  // draw vertical lines
  for ($x = $x_start; $x < $img_width; $x += $x_size) {
    imageline($im, $x, 0, $x, $img_height, $linecolor);
  }

  // return captcha image handle
  return $im;
}
?>

We need a method for generating random four character strings when the captcha is created and displayed to the user. This function will do the trick.

<?php
function secret_key($length=4) {
  $salt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
  srand((double)microtime()*1000000);
  $i = 0;
  $skey = "";
  while ($i < $length) {
    $num = rand() % strlen($salt);
    $tmp = substr($salt, $num, 1);
    $skey .= $tmp;
    $i++;
  }
  return $skey;
}
?>

With everything in place, we can generate the secret key, create the captcha, and finally display it to the user using this code.

<?php
// set headers
header("Content-type: image/png");
header("Cache-Control: no-cache");
header("Pragma: no-cache");

// generate secret
$skey = secret_key();

// create captcha and output to browser as PNG image
$im = captcha_image($skey);
@imagepng($im);
@imagedestroy($im);
?>

Here is an example of the code in action. The style looks very similar to the images used on Yahoo’s Overture.

Captcha Demo »

Now you know how to create a captcha, so what about verifying the input against the captcha value? This can be accomplished a variety of ways and everyone tends to have their preference.

• One method is to save the secret key in a session variable. As the image is created, store the key in a session variable and once the form is submitted, check the user’s value against the one stored in the session. If they match, proceed but if they fail, return an error and don’t process the form data.
• If you don’t want to use sessions, you could try using temp files. Store the key in a temp file and pass some value as a query string identifying to the script that the key is in that file. Read in the key and MD5 or SHA1 crypt the key and save it in a hidden form field. When the form is submitted, compare the hashed key against the user input (which you will also hash). Process the form data if the keys match.

You can download the provided source file. Use the PHP file as an image source in your HTML IMG tag.

<img src="http://www.yourdomain.com/captcha.php">

Don’t forget to edit the path to the TrueType font you want to use in the captcha_image function. Failure to do so will lead to missing image characters.

Source Files: captcha.zip