diff --git a/privatemsg.module b/privatemsg.module
index 995b97b..cde606c 100644
--- a/privatemsg.module
+++ b/privatemsg.module
@@ -1421,6 +1421,13 @@ function privatemsg_privatemsg_block_message($author, $recipients, $context = ar
         'message' => t('%recipient has disabled private message receiving.', array('%recipient' => privatemsg_recipient_format($recipient, array('plain' => TRUE)))),
       );
     }
+    // Do not send private messages to blocked users.
+    else if (isset($recipient->status) && (!$recipient->status)) {
+      $blocked[] = array(
+        'recipient' => 'user_' . $recipient->uid,
+        'message' => t('%recipient has disabled his or her account.', array('%recipient' => privatemsg_recipient_format($recipient, array('plain' => TRUE)))),
+      );
+    }
   }
 
   return $blocked;
diff --git a/privatemsg.test b/privatemsg.test
index 8e15c98..cc236d9 100644
--- a/privatemsg.test
+++ b/privatemsg.test
@@ -76,7 +76,8 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
    * Create user with 'read privatemsg' permission. Try to access mailbox and see if it gives allows access
    */
   function testPrivatemsgReadPrivatemsgPermission() {
-    $user_no_read_msg = $this->drupalCreateUser(); // set up user with default permissions (meaning: no read privatemsg permission
+    // Set up a user with the default permissions.
+    $user_no_read_msg = $this->drupalCreateUser();
     $author     = $this->drupalCreateUser(array('write privatemsg', 'read privatemsg'));
     $recipient  = $this->drupalCreateUser(array('read privatemsg'));
     $no_recipient  = $this->drupalCreateUser(array('read privatemsg'));
@@ -112,12 +113,15 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
    * Create user with 'write privatemsg' permission. Try to access Write New Message page and see if it gives allows access
    */
   function testPrivatemsgWritePrivatemsgPermission() {
-    $user_no_write_msg = $this->drupalCreateUser(); // set up user with default permissions (meaning: no read privatemsg permission
+    // Set up a user with the default permissions (no "read privatemsg"
+    // permission).
+    $user_no_write_msg = $this->drupalCreateUser();
     $this->drupalLogin($user_no_write_msg);
     $this->drupalGet('messages/new');
     $this->assertResponse(403, t('HTTP Response 403: Access to Write New Message page was blocked to user without "<em>write privatemsg</em>" permission'));
 
-    $user_write_msg = $this->drupalCreateUser(array('write privatemsg')); // set up user with write privatemsg permissions
+    // Set up a user with "write privatemsg" permissions.
+    $user_write_msg = $this->drupalCreateUser(array('write privatemsg'));
     $this->drupalLogin($user_write_msg);
     $this->drupalGet('messages/new');
     $this->assertResponse(200, t('HTTP Response 200: Access to Write New Message page was authorized to user with "<em>write privatemsg</em>" permission'));
@@ -242,6 +246,11 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
     $author     = $this->drupalCreateUser(array('write privatemsg', 'select text format for privatemsg', filter_permission_name(filter_format_load('full_html'))));
     $recipient  = $this->drupalCreateUser(array('read privatemsg'));
     $recipient2  = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg'));
+    // Set up a user with "read/write privatemsg" permissions.
+    $blocked_recipient = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg'));
+    // Block one of the recipients to make sure that no messages are delivered
+    // to invalid recipients.
+    user_save($blocked_recipient, array('status' => 0));
 
     // Login author and go to new message form.
     $this->drupalLogin($author);
@@ -271,6 +280,12 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
       'subject'     => $this->randomName(20),
       'body[value]' => $this->randomName(100),
     );
+    // Blocked recipient
+    $editblocked = array(
+      'recipient'   => $blocked_recipient,
+      'subject'     => $this->randomName(20),
+      'body[value]' => $this->randomName(100),
+    );
     // Empty body.
     $editnobody = array(
       'recipient'   => $recipient->name,
@@ -324,6 +339,10 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
     $this->assertText(t('You must include at least one valid recipient.'), 'Message was not sent.');
     $this->assertText(t('The following recipients will not receive this private message: @recipients.', array('@recipients' => $editinvalid['recipient'])), 'Message about non-existing user displayed.');
 
+    $this->drupalPost('messages/new', $editblocked, t('Send message'));
+    $this->assertText(t('%recipient has disabled his or her account.', array('%recipient' => $editblocked->name)), 'Message about blocked user displayed.');
+    $this->assertText(t('You are not allowed to send this message because all recipients are blocked.'), 'Message was not sent.');
+
     $this->drupalPost('messages/new', $editnobody, t('Send message'));
     $this->assertText(t('A message has been sent to @recipients.', array('@recipients' => $recipient->name)), 'Message sent confirmation displayed.');
 
@@ -416,6 +435,14 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
     $this->assertText($edit2['body[value]'], 'Found message body.');
     // Confirm that we can read the reply that was sent.
     $this->assertText($reply['body[value]'], 'Found reply body.');
+
+    // Block the author.
+    user_save($author, array('status' => 0));
+    // Navigate into the message.
+    $this->drupalGet('messages');
+    $this->clickLink($edit2['subject']);
+    // Confirm that the reply form is not shown.
+    $this->assertNoText(t('Reply to thread:'), 'Reply form is not displayed.');
   }
 
   /**
@@ -423,9 +450,12 @@ class PrivatemsgTestCase extends PrivatemsgBaseTestCase {
    */
   function testDisablePrivatemsg() {
     $admin_user = $this->drupalCreateUser(array('administer permissions'));
-    $enableduser = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg')); // set up user with read/write privatemsg permissions
-    $enableduser2 = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg')); // set up user with read/write privatemsg permissions
-    $disableduser = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg', 'allow disabling privatemsg')); // set up user with read/write privatemsg permissions
+    // Set up a user with "read/write privatemsg" permissions.
+    $enableduser = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg'));
+    // Set up a user with "read/write privatemsg" permissions.
+    $enableduser2 = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg'));
+    // Set up a user with "read/write privatemsg" permissions.
+    $disableduser = $this->drupalCreateUser(array('read privatemsg', 'write privatemsg', 'allow disabling privatemsg'));
 
     // Create a message between the users that we can use to test
     $return = privatemsg_new_thread(array($disableduser), $this->randomName(20), $this->randomName(100), array('author' => $enableduser));