diff --git a/MailLibrary/ContactList.php b/MailLibrary/ContactList.php
index a408bca..2f2a362 100644
--- a/MailLibrary/ContactList.php
+++ b/MailLibrary/ContactList.php
@@ -11,9 +11,9 @@
 class ContactList implements Iterator, Countable
 {
 	/** @var Contact[] */
-	protected $contacts;
+	protected $contacts = [];
 
-	protected $builtContacts;
+	protected $builtContacts = [];
 
 	public function addContact($mailbox = NULL, $host = NULL, $personal = NULL, $adl = NULL)
 	{
diff --git a/MailLibrary/Drivers/ImapDriver.php b/MailLibrary/Drivers/ImapDriver.php
index eb059e7..8647979 100644
--- a/MailLibrary/Drivers/ImapDriver.php
+++ b/MailLibrary/Drivers/ImapDriver.php
@@ -10,6 +10,7 @@
 use greeny\MailLibrary\Mailbox;
 use greeny\MailLibrary\Structures\IStructure;
 use greeny\MailLibrary\Structures\ImapStructure;
+use Nette\Utils\Strings;
 use greeny\MailLibrary\Mail;
 use DateTime;
 
@@ -227,18 +228,21 @@ public function checkFilter($key, $value = NULL) {
 	public function getHeaders($mailId)
 	{
 		$raw = imap_fetchheader($this->resource, $mailId, FT_UID);
-		$lines = explode("\n", $raw);
+		$lines = explode("\n", Strings::fixEncoding($raw));
 		$headers = array();
 		$lastHeader = NULL;
+		
+		// normalize headers
 		foreach($lines as $line) {
-			if(mb_substr($line, 0, 1, 'UTF-8') === " ") {
-				$headers[$lastHeader] .= $line;
+			$firstCharacter = mb_substr($line, 0, 1, 'UTF-8'); // todo: correct assumption that string must be UTF-8 encoded?
+			if(preg_match('/[\pZ\pC]/u', $firstCharacter) === 1) { // search for UTF-8 whitespaces
+				$headers[$lastHeader] .= " " . Strings::trim($line);
 			} else {
 				$parts = explode(':', $line);
-				$name = $parts[0];
+				$name = Strings::trim($parts[0]);
 				unset($parts[0]);
 
-				$headers[$name] = implode(':', $parts);
+				$headers[$name] = Strings::trim(implode(':', $parts));
 				$lastHeader = $name;
 			}
 		}
@@ -254,14 +258,14 @@ public function getHeaders($mailId)
 				$text = '';
 				foreach($decoded as $part) {
 					if($part->charset !== 'UTF-8' && $part->charset !== 'default') {
-						$text .= mb_convert_encoding($part->text, 'UTF-8', $part->charset);
+						$text .= @mb_convert_encoding($part->text, 'UTF-8', $part->charset); // todo: handle this more properly
 					} else {
 						$text .= $part->text;
 					}
 				}
 
 				$headers[$key] = trim($text);
-			} else if(in_array(strtolower($key), self::$contactHeaders)) {
+			} /*else if(in_array(strtolower($key), self::$contactHeaders)) {
 				$contacts = imap_rfc822_parse_adrlist(imap_utf8(trim($header)), 'UNKNOWN_HOST');
 				$list = new ContactList();
 				foreach($contacts as $contact) {
@@ -274,7 +278,7 @@ public function getHeaders($mailId)
 				}
 				$list->build();
 				$headers[$key] = $list;
-			} else {
+			}*/ else {
 				$headers[$key] = trim(imap_utf8($header));
 			}
 		}
diff --git a/MailLibrary/Mail.php b/MailLibrary/Mail.php
index 0431948..4991d55 100644
--- a/MailLibrary/Mail.php
+++ b/MailLibrary/Mail.php
@@ -124,7 +124,12 @@ public function getHeaders()
 	public function getHeader($name)
 	{
 		$this->headers !== NULL || $this->initializeHeaders();
-		return $this->headers[$this->formatHeaderName($name)];
+		$index = $this->formatHeaderName($name);
+		if(isset($this->headers[$index])) {
+			return $this->headers[$index];
+		} else {
+			return NULL;
+		}
 	}
 
 	/**
diff --git a/MailLibrary/loader.php b/MailLibrary/loader.php
index 998517c..e11bb40 100644
--- a/MailLibrary/loader.php
+++ b/MailLibrary/loader.php
@@ -6,24 +6,24 @@
 require_once "exceptions.php";
 
 spl_autoload_register(function ($type) {
-        static $paths = array(
-            'greeny\maillibrary\connection' => 'Connection.php',
-            'greeny\maillibrary\mailbox' => 'Mailbox.php',
-            'greeny\maillibrary\selection' => 'Selection.php',
-            'greeny\maillibrary\mail' => 'Mail.php',
-            'greeny\maillibrary\contactlist' => 'ContactList.php',
-            'greeny\maillibrary\contact' => 'Contact.php',
-            'greeny\maillibrary\attachment' => 'Attachment.php',
-            'greeny\maillibrary\structures\istructure' => 'Structures/IStructure.php',
-            'greeny\maillibrary\structures\imapstructure' => 'Structures/ImapStructure.php',
-            'greeny\maillibrary\drivers\idriver' => 'Drivers/IDriver.php',
-            'greeny\maillibrary\drivers\imapdriver' => 'Drivers/ImapDriver.php',
-            'greeny\maillibrary\extensions\maillibraryextension' => 'Extensions/MailLibraryExtension.php',
-        );
+	static $paths = array(
+		'greeny\maillibrary\connection' => 'Connection.php',
+		'greeny\maillibrary\mailbox' => 'Mailbox.php',
+		'greeny\maillibrary\selection' => 'Selection.php',
+		'greeny\maillibrary\mail' => 'Mail.php',
+		'greeny\maillibrary\contactlist' => 'ContactList.php',
+		'greeny\maillibrary\contact' => 'Contact.php',
+		'greeny\maillibrary\attachment' => 'Attachment.php',
+		'greeny\maillibrary\structures\istructure' => 'Structures/IStructure.php',
+		'greeny\maillibrary\structures\imapstructure' => 'Structures/ImapStructure.php',
+		'greeny\maillibrary\drivers\idriver' => 'Drivers/IDriver.php',
+		'greeny\maillibrary\drivers\imapdriver' => 'Drivers/ImapDriver.php',
+		'greeny\maillibrary\extensions\maillibraryextension' => 'Extensions/MailLibraryExtension.php',
+	);
 
-        $type = ltrim(strtolower($type), '\\'); // PHP namespace bug #49143
+	$type = ltrim(strtolower($type), '\\'); // PHP namespace bug #49143
 
-        if (isset($paths[$type])) {
-                require_once __DIR__ . '/' . $paths[$type];
-        }
+	if (isset($paths[$type])) {
+		require_once __DIR__ . '/' . $paths[$type];
+	}
 });
\ No newline at end of file
diff --git a/README.md b/README.md
index 79fc5d9..08f3980 100644
--- a/README.md
+++ b/README.md
@@ -3,4 +3,17 @@ MailLibrary
 
 A PHP library for downloading mails from server.
 
-Documentation can be found at http://greeny.github.io/MailLibrary/.
\ No newline at end of file
+Documentation can be found at http://greeny.github.io/MailLibrary/.
+
+Testing
+-------
+
+Install dependencies using composer and then run following in library root directory.
+
+````cmd
+# Unix
+vendor\bin\tester -c tests\php-unix.ini tests
+
+# Windows
+vendor\bin\tester -c tests\php-windows.ini tests
+````
diff --git a/composer.json b/composer.json
index 8b0751c..d04e0ac 100644
--- a/composer.json
+++ b/composer.json
@@ -12,9 +12,11 @@
         "files": ["MailLibrary/loader.php"]
     },
     "require": {
-        "php": ">= 5.3.0"
+        "php": ">= 5.3.0",
+        "ext-imap": "*",
+        "nette/utils": "~2.2"
     },
     "require-dev": {
         "nette/tester": "@dev"
     }
-}
\ No newline at end of file
+}
diff --git a/tests/php-unix.ini b/tests/php-unix.ini
new file mode 100644
index 0000000..c758598
--- /dev/null
+++ b/tests/php-unix.ini
@@ -0,0 +1,5 @@
+[PHP]
+;extension_dir = "./ext"
+extension=mbstring.so
+extension=imap.so
+date.timezone = "Europe/Prague"
diff --git a/tests/php-windows.ini b/tests/php-windows.ini
new file mode 100644
index 0000000..f601ad4
--- /dev/null
+++ b/tests/php-windows.ini
@@ -0,0 +1,5 @@
+[PHP]
+extension_dir = "./ext"
+extension=php_mbstring.dll
+extension=php_imap.dll
+date.timezone = "Europe/Prague"