diff --git a/docs/changelog/7.x.x.txt b/docs/changelog/7.x.x.txt
index 38c6a3884..79cb309a7 100644
--- a/docs/changelog/7.x.x.txt
+++ b/docs/changelog/7.x.x.txt
@@ -5,6 +5,7 @@
  - fixed #11658: tmpl var message missing in template help for the cart
  - fixed #11628: Message Board: Last Post doesn't show up in CS Thread List
  - fixed #11646: Post and Thread Last Post
+ - fixed #11626: Duplicate messages from Collab Systems
 
 7.9.7
  - added #11571: Allow return from photo edit view to gallery edit view
diff --git a/docs/upgrades/packages-7.9.8/root_import_collaboration.wgpkg b/docs/upgrades/packages-7.9.8/root_import_collaboration.wgpkg
new file mode 100644
index 000000000..98633a498
Binary files /dev/null and b/docs/upgrades/packages-7.9.8/root_import_collaboration.wgpkg differ
diff --git a/lib/WebGUI/Asset/Post.pm b/lib/WebGUI/Asset/Post.pm
index f18360159..f21ea9b47 100644
--- a/lib/WebGUI/Asset/Post.pm
+++ b/lib/WebGUI/Asset/Post.pm
@@ -1633,6 +1633,7 @@ sub www_edit {
     $var{'archive.form'} = WebGUI::Form::yesNo($session, {
         name=>"archive"
     });
+    $var{'isSubscribedToCs'} = $self->getThread->getParent->isSubscribed;
 	$var{'form.header'} .= WebGUI::Form::hidden($session, {
         name=>"proceed", 
         value=>"showConfirmation"
diff --git a/lib/WebGUI/Help/Asset_Post.pm b/lib/WebGUI/Help/Asset_Post.pm
index da15b68f8..63758f58b 100644
--- a/lib/WebGUI/Help/Asset_Post.pm
+++ b/lib/WebGUI/Help/Asset_Post.pm
@@ -27,6 +27,7 @@ our $HELP = {
             { 'name' => 'reply.synopsis' },
             { 'name' => 'reply.content' },
             { 'name' => 'reply.userDefinedN' },
+            { 'name' => 'isSubscribedToCs' },
             { 'name' => 'subscribe.form' },
             { 'name' => 'isNewThread' },
             { 'name' => 'archive.form' },
diff --git a/lib/WebGUI/i18n/English/Asset_Post.pm b/lib/WebGUI/i18n/English/Asset_Post.pm
index 05d331502..786bd0132 100644
--- a/lib/WebGUI/i18n/English/Asset_Post.pm
+++ b/lib/WebGUI/i18n/English/Asset_Post.pm
@@ -48,6 +48,12 @@ editing an existing Post.|,
 		lastUpdated => 1149829706,
 	},
 
+	'isSubscribedToCs' => {
+		message => q|A boolean which will be true if the current user is subscribed to the CS containing this Post.|,
+        context => q|Template variable description|,
+		lastUpdated => 1149829706,
+	},
+
 	'subscribe.form' => {
 		message => q|A yes/no button to allow the user to subscribe to the thread this post belongs to.|,
 		lastUpdated => 1149829706,