idn have to be converted before being used

lib/private/mail.php

@@ -73,6 +73,7 @@ class OC_Mail {
 		$mailo->FromName = $fromname;;
 		$mailo->Sender = $fromaddress;
 		try {
+			$toaddress = self::buildAsciiEmail($toaddress);
 			$mailo->AddAddress($toaddress, $toname);
 
 			if($ccaddress<>'') $mailo->AddCC($ccaddress, $ccname);
@@ -125,6 +126,22 @@ class OC_Mail {
 	 * @return bool
 	 */
 	public static function ValidateAddress($emailAddress) {
+		$emailAddress = self::buildAsciiEmail($emailAddress);
 		return PHPMailer::ValidateAddress($emailAddress);
 	}
+
+	/**
+	 * IDN domains will be properly converted to ascii domains.
+	 *
+	 * @param string $emailAddress
+	 * @return string
+	 */
+	public static function buildAsciiEmail($emailAddress) {
+
+		list($name, $domain) = explode('@', $emailAddress, 2);
+		$domain = idn_to_ascii($domain);
+
+		return "$name@$domain";
+	}
+
 }

tests/lib/mail.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * Copyright (c) 2014 Thomas Müller <deepdiver@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+class Test_Mail extends PHPUnit_Framework_TestCase {
+
+	/**
+	 * @dataProvider buildAsciiEmailProvider
+	 * @param $expected
+	 * @param $address
+	 */
+	public function testBuildAsciiEmail($expected, $address) {
+		$actual = \OC_Mail::buildAsciiEmail($address);
+		$this->assertEquals($expected, $actual);
+	}
+
+	function buildAsciiEmailProvider() {
+		return array(
+			array('info@example.com', 'info@example.com'),
+			array('info@xn--cjr6vy5ejyai80u.com', 'info@國際化域名.com'),
+			array('info@xn--mller-kva.de', 'info@müller.de'),
+			array('info@xn--mller-kva.xn--mller-kva.de', 'info@müller.müller.de'),
+		);
+	}
+
+}