Encoding text as quoted-printable in MIME email

[absynthe]

I don't want to install IMAP and use imap_8bit() to encode plain text or html message as quoted-printable
(friendly french special characters encoding :-) in MIME email. So I made this function to do the job.
I haven't fully tested it (like microtime with long mails). I send html message as 7-bit, so I didn't try yet with html.
If you have good html practise, you don't really need to encode html as quote-printable as it only uses 7-bit chars.
Try it, and tell me if any bugs or way to improve.
F.Touchard

function qp_encoding($Message) {

/* Build (most polpular) Extended ASCII Char/Hex MAP (characters >127 & <255) */
for ($i=0; $i<127; $i++) {
	$CharList[$i] = "/".chr($i+128)."/";
	$HexList[$i] = "=".strtoupper(bin2hex(chr($i+128)));
}

/* Encode equal sign & 8-bit characters as equal signs followed by their hexadecimal values */
$Message = str_replace("=", "=3D", $Message);
$Message = preg_replace($CharList, $HexList, $Message);

/* Lines longer than 76 characters (size limit for quoted-printable Content-Transfer-Encoding)
    will be cut after character 75 and an equals sign is appended to these lines. */ 
$MessageLines = split("\n", $Message);
$Message_qp = "";
while(list(, $Line) = each($MessageLines)) {
	if (strlen($Line) > 75) {
		$Pointer = 0;		
		while ($Pointer <= strlen($Line)) {
			$Offset = 0;
			if (preg_match("/^=(3D|([8-9A-F]{1}[0-9A-F]{1}))$/", substr($Line, ($Pointer+73), 3))) $Offset=-2;
			if (preg_match("/^=(3D|([8-9A-F]{1}[0-9A-F]{1}))$/", substr($Line, ($Pointer+74), 3))) $Offset=-1;
			$Message_qp.= substr($Line, $Pointer, (75+$Offset))."=\n";
			if ((strlen($Line) - ($Pointer+75)) <= 75) {				
				$Message_qp.= substr($Line, ($Pointer+75+$Offset))."\n";
				break 1;
			}
			$Pointer+= 75+$Offset;
		}
	} else {
		$Message_qp.= $Line."\n";
	}
}		
return $Message_qp;

}