diff --git a/phpBB/includes/functions_privmsgs.php b/phpBB/includes/functions_privmsgs.php
index b08d6e7f5c..c99f40d453 100644
--- a/phpBB/includes/functions_privmsgs.php
+++ b/phpBB/includes/functions_privmsgs.php
@@ -208,7 +208,7 @@ function get_folder($user_id, $folder_id = false)
 		);
 	}
 
-	if ($folder_id !== false && !isset($folder[$folder_id]))
+	if ($folder_id !== false && $folder_id !== PRIVMSGS_HOLD_BOX && !isset($folder[$folder_id]))
 	{
 		trigger_error('UNKNOWN_FOLDER');
 	}
diff --git a/tests/functional/private_messages_test.php b/tests/functional/private_messages_test.php
new file mode 100644
index 0000000000..15aa2b681a
--- /dev/null
+++ b/tests/functional/private_messages_test.php
@@ -0,0 +1,65 @@
+<?php
+/**
+*
+* @package testing
+* @copyright (c) 2014 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @group functional
+*/
+class phpbb_functional_private_messages_test extends phpbb_functional_test_case
+{
+	public function test_setup_config()
+	{
+		$this->login();
+		$this->admin_login();
+
+		$crawler = self::request('GET', "adm/index.php?sid={$this->sid}&i=board&mode=message");
+
+		$form = $crawler->selectButton('Submit')->form();
+		$values = $form->getValues();
+
+		// Set the maximum number of private messages per folder to 1
+		$values['config[pm_max_msgs]'] = 1;
+
+		$form->setValues($values);
+
+		$crawler = self::submit($form);
+		$this->assertContains($this->lang('CONFIG_UPDATED'), $crawler->filter('.successbox')->text());
+	}
+
+	public function test_inbox_full()
+	{
+		$this->login();
+		$message_id = $this->create_private_message('Test private message #1', 'This is a test private message sent by the testing framework.', array(2));
+
+		$crawler = self::request('GET', "ucp.php?i=pm&mode=view&sid{$this->sid}&p={$message_id}");
+		$this->assertContains($this->lang('UCP_PM_VIEW'), $crawler->filter('html')->text());
+
+		$message_id = $this->create_private_message('Test private message #2', 'This is a test private message sent by the testing framework.', array(2));
+
+		$crawler = self::request('GET', "ucp.php?i=pm&mode=view&sid{$this->sid}&p={$message_id}");
+		$this->assertContains($this->lang('NO_AUTH_READ_HOLD_MESSAGE'), $crawler->filter('html')->text());
+	}
+
+	public function test_restore_config()
+	{
+		$this->login();
+		$this->admin_login();
+
+		$crawler = self::request('GET', "adm/index.php?sid={$this->sid}&i=board&mode=message");
+
+		$form = $crawler->selectButton('Submit')->form();
+		$values = $form->getValues();
+
+		$values['config[pm_max_msgs]'] = 50;
+
+		$form->setValues($values);
+
+		$crawler = self::submit($form);
+		$this->assertContains($this->lang('CONFIG_UPDATED'), $crawler->filter('.successbox')->text());
+	}
+}
diff --git a/tests/test_framework/phpbb_functional_test_case.php b/tests/test_framework/phpbb_functional_test_case.php
index 5dfe07d380..4522674649 100644
--- a/tests/test_framework/phpbb_functional_test_case.php
+++ b/tests/test_framework/phpbb_functional_test_case.php
@@ -665,6 +665,64 @@ class phpbb_functional_test_case extends phpbb_test_case
 	{
 		$this->add_lang('posting');
 
+		$crawler = $this->submit_message($posting_url, $posting_contains, $form_data);
+
+		$this->assertContains($this->lang('POST_STORED'), $crawler->filter('html')->text());
+		$url = $crawler->selectLink($this->lang('VIEW_MESSAGE', '', ''))->link()->getUri();
+
+		return array(
+			'topic_id'	=> $this->get_parameter_from_link($url, 't'),
+			'post_id'	=> $this->get_parameter_from_link($url, 'p'),
+		);
+	}
+
+	/**
+	* Creates a private message
+	*
+	* Be sure to login before creating
+	*
+	* @param string $subject
+	* @param string $message
+	* @param array $to
+	* @param array $additional_form_data Any additional form data to be sent in the request
+	* @return int private_message_id
+	*/
+	public function create_private_message($subject, $message, $to, $additional_form_data = array())
+	{
+		$this->add_lang(array('ucp', 'posting'));
+
+		$posting_url = "ucp.php?i=pm&mode=compose&sid={$this->sid}";
+
+		$form_data = array_merge(array(
+			'subject'		=> $subject,
+			'message'		=> $message,
+			'post'			=> true,
+		), $additional_form_data);
+
+		foreach ($to as $user_id)
+		{
+			$form_data['address_list[u][' . $user_id . ']'] = 'to';
+		}
+
+		$crawler = self::submit_message($posting_url, 'POST_NEW_PM', $form_data);
+
+		$this->assertContains($this->lang('MESSAGE_STORED'), $crawler->filter('html')->text());
+		$url = $crawler->selectLink($this->lang('VIEW_PRIVATE_MESSAGE', '', ''))->link()->getUri();
+
+		return $this->get_parameter_from_link($url, 'p');
+	}
+
+	/**
+	* Helper for submitting a message (post or private message)
+	*
+	* @param string $posting_url
+	* @param string $posting_contains
+	* @param array $form_data
+	* @return \Symfony\Component\DomCrawler\Crawler the crawler object
+	*/
+	protected function submit_message($posting_url, $posting_contains, $form_data)
+	{
+
 		$crawler = self::request('GET', $posting_url);
 		$this->assertContains($this->lang($posting_contains), $crawler->filter('html')->text());
 
@@ -689,14 +747,7 @@ class phpbb_functional_test_case extends phpbb_test_case
 		// I use a request because the form submission method does not allow you to send data that is not
 		// contained in one of the actual form fields that the browser sees (i.e. it ignores "hidden" inputs)
 		// Instead, I send it as a request with the submit button "post" set to true.
-		$crawler = self::request('POST', $posting_url, $form_data);
-		$this->assertContains($this->lang('POST_STORED'), $crawler->filter('html')->text());
-		$url = $crawler->selectLink($this->lang('VIEW_MESSAGE', '', ''))->link()->getUri();
-
-		return array(
-			'topic_id'	=> $this->get_parameter_from_link($url, 't'),
-			'post_id'	=> $this->get_parameter_from_link($url, 'p'),
-		);
+		return self::request('POST', $posting_url, $form_data);
 	}
 
 	/**