diff --git a/app/models/issue.rb b/app/models/issue.rb
index 419c6cdc7..a1c46cadf 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -190,9 +190,9 @@ class Issue < ActiveRecord::Base
   # Returns the mail adresses of users that should be notified for the issue
   def recipients
     recipients = project.recipients
-    # Author and assignee are always notified
-    recipients << author.mail if author
-    recipients << assigned_to.mail if assigned_to
+    # Author and assignee are always notified unless they have been locked
+    recipients << author.mail if author && author.active?
+    recipients << assigned_to.mail if assigned_to && assigned_to.active?
     recipients.compact.uniq
   end
   
diff --git a/app/models/message_observer.rb b/app/models/message_observer.rb
index 1c311e25f..c26805c1b 100644
--- a/app/models/message_observer.rb
+++ b/app/models/message_observer.rb
@@ -18,7 +18,7 @@
 class MessageObserver < ActiveRecord::Observer
   def after_create(message)
     # send notification to the authors of the thread
-    recipients = ([message.root] + message.root.children).collect {|m| m.author.mail if m.author}
+    recipients = ([message.root] + message.root.children).collect {|m| m.author.mail if m.author && m.author.active?}
     # send notification to the board watchers
     recipients += message.board.watcher_recipients
     recipients = recipients.compact.uniq
diff --git a/vendor/plugins/acts_as_watchable/lib/acts_as_watchable.rb b/vendor/plugins/acts_as_watchable/lib/acts_as_watchable.rb
index c789017e5..53e4455cf 100644
--- a/vendor/plugins/acts_as_watchable/lib/acts_as_watchable.rb
+++ b/vendor/plugins/acts_as_watchable/lib/acts_as_watchable.rb
@@ -37,7 +37,7 @@ module Redmine
         end
         
         def watcher_recipients
-          self.watchers.collect { |w| w.user.mail }
+          self.watchers.collect { |w| w.user.mail if w.user.active? }.compact
         end
 
         module ClassMethods