Index: class.t3lib_htmlmail.php
===================================================================
--- class.t3lib_htmlmail.php	(revision 6669)
+++ class.t3lib_htmlmail.php	(working copy)
@@ -1433,11 +1433,33 @@
 		$c = count($tags);
 		foreach($tags as $tag) {
 			$c--;
-			$regexp .= '<' . sql_regcase($tag) . "[[:space:]]" . (($c) ? '|' : '');
+			$regexp .= '<' . $this->sql_regcase($tag) . "[[:space:]]" . (($c) ? '|' : '');
 		}
 		return $regexp . '/';
 	}
 
+	/**
+	* replacing the deprecated function sql_regex for php 5.3
+	* 
+	* @param string $string
+	* @param string $encoding
+	* @return string regex 
+	*/
+	private function sql_regcase($string,$encoding='auto'){
+		$ret = '';
+		if (function_exists('sql_regcase')) {
+			$ret = sql_regcase($tag);
+		} else {
+			$max=mb_strlen($item,$encoding);
+			for ($i = 0; $i < $max; $i++) {
+				$char=mb_substr($item,$i,1,$encoding);
+				$up=mb_strtoupper ($char,$encoding);
+				$low=mb_strtolower($char,$encoding);
+				$ret.=($up!=$low)?'['.$up.$low.']' : $char;
+			}
+		}
+		return $ret;
+	} 
 
 	/**
 	 * This function analyzes a HTML tag