diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component.php
index f33b628a7..cb08c0061 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component.php
@@ -249,7 +249,7 @@ class Component extends Node
         $result = [];
         foreach ($this->children as $childGroup) {
             foreach ($childGroup as $child) {
-                if ($child instanceof Property && strtoupper($child->group) === $group) {
+                if ($child instanceof Property && $child->group && strtoupper($child->group) === $group) {
                     $result[] = $child;
                 }
             }
diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component/VCard.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component/VCard.php
index eac789842..90a6df72f 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component/VCard.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Component/VCard.php
@@ -291,6 +291,11 @@ class VCard extends VObject\Document
                     $this->FN = (string) $this->ORG;
                     $repaired = true;
 
+                // Otherwise, the NICKNAME property may work
+                } elseif (isset($this->NICKNAME)) {
+                    $this->FN = (string) $this->NICKNAME;
+                    $repaired = true;
+
                 // Otherwise, the EMAIL property may work
                 } elseif (isset($this->EMAIL)) {
                     $this->FN = (string) $this->EMAIL;
diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Parameter.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Parameter.php
index 4f1e860d4..7e4d55743 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Parameter.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Parameter.php
@@ -335,7 +335,7 @@ class Parameter extends Node
      */
     public function xmlSerialize(Xml\Writer $writer)
     {
-        foreach (is_array($this->value) ? $this->value : explode(',', $this->value) as $value) {
+        foreach (explode(',', $this->value) as $value) {
             $writer->writeElement('text', $value);
         }
     }
diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Property/ICalendar/CalAddress.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Property/ICalendar/CalAddress.php
index 2dbbc6eaf..c90967d79 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Property/ICalendar/CalAddress.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Property/ICalendar/CalAddress.php
@@ -53,7 +53,11 @@ class CalAddress extends Text
             return $input;
         }
         list($schema, $everythingElse) = explode(':', $input, 2);
+        $schema = strtolower($schema);
+        if ('mailto' === $schema) {
+            $everythingElse = strtolower($everythingElse);
+        }
 
-        return strtolower($schema).':'.$everythingElse;
+        return $schema.':'.$everythingElse;
     }
 }
diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/StringUtil.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/StringUtil.php
index 2333d6ab9..b04539e4a 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/StringUtil.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/StringUtil.php
@@ -40,23 +40,11 @@ class StringUtil
      */
     public static function convertToUTF8($str)
     {
-        $encoding = mb_detect_encoding($str, ['UTF-8', 'ISO-8859-1', 'WINDOWS-1252'], true);
-
-        switch ($encoding) {
-            case 'ISO-8859-1':
-                $newStr = utf8_encode($str);
-                break;
-            /* Unreachable code. Not sure yet how we can improve this
-             * situation.
-            case 'WINDOWS-1252' :
-                $newStr = iconv('cp1252', 'UTF-8', $str);
-                break;
-             */
-            default:
-                 $newStr = $str;
+        if (!mb_check_encoding($str, 'UTF-8') && mb_check_encoding($str, 'ISO-8859-1')) {
+            $str = mb_convert_encoding($str, 'UTF-8', 'ISO-8859-1');
         }
 
         // Removing any control characters
-        return preg_replace('%(?:[\x00-\x08\x0B-\x0C\x0E-\x1F\x7F])%', '', $newStr);
+        return preg_replace('%(?:[\x00-\x08\x0B-\x0C\x0E-\x1F\x7F])%', '', $str);
     }
 }
diff --git a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Version.php b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Version.php
index 64938bf0b..ff8cf49c2 100644
--- a/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Version.php
+++ b/snappymail/v/0.0.0/app/libraries/Sabre/VObject/Version.php
@@ -14,5 +14,5 @@ class Version
     /**
      * Full version number.
      */
-    const VERSION = '4.4.1';
+    const VERSION = '4.4.2';
 }