diff --git a/docs/changelog/7.x.x.txt b/docs/changelog/7.x.x.txt
index ad57aaec5..b30429113 100644
--- a/docs/changelog/7.x.x.txt
+++ b/docs/changelog/7.x.x.txt
@@ -1,4 +1,5 @@
 7.7.19
+ - fixed #10838: Forwarded forum post email to new CS adds reply to original thread
  - fixed #10872: Purging an asset leaves old version tags
  - fixed #10867: EMS: can't set Ticket time
  - fixed #10855: Bug in submitting data to ITransact
diff --git a/lib/WebGUI/Workflow/Activity/GetCsMail.pm b/lib/WebGUI/Workflow/Activity/GetCsMail.pm
index 109f5ffda..ab7aeaac2 100644
--- a/lib/WebGUI/Workflow/Activity/GetCsMail.pm
+++ b/lib/WebGUI/Workflow/Activity/GetCsMail.pm
@@ -204,7 +204,12 @@ sub execute {
 		my $post = undef;
 		if ($message->{inReplyTo} && $message->{inReplyTo} =~ m/cs\-([\w_-]{22})\@/) {
 			my $id = $1;
-			$post = WebGUI::Asset->newByDynamicClass($self->session, $id);
+            my $repliedPost = WebGUI::Asset->newByDynamicClass($self->session, $id);
+            if ($repliedPost
+                && $repliedPost->isa('WebGUI::Asset::Post')
+                && $repliedPost->getThread->getParent->getId eq $cs->getId) {
+                $post = $repliedPost;
+            }
 		}
 
 		if (defined $post && $cs->get("allowReplies") && $user->isInGroup($cs->get("postGroupId")) && (!$cs->get("requireSubscriptionForEmailPosting") || $user->isInGroup($cs->get("subscriptionGroupId")) || $user->isInGroup($post->get("subscriptionGroupId")))) {
diff --git a/t/Workflow/Activity/GetCsMail.t b/t/Workflow/Activity/GetCsMail.t
new file mode 100644
index 000000000..014ae95de
--- /dev/null
+++ b/t/Workflow/Activity/GetCsMail.t
@@ -0,0 +1,154 @@
+# vim:syntax=perl
+#-------------------------------------------------------------------
+# WebGUI is Copyright 2001-2009 Plain Black Corporation.
+#-------------------------------------------------------------------
+# Please read the legal notices (docs/legal.txt) and the license
+# (docs/license.txt) that came with this distribution before using
+# this software.
+#------------------------------------------------------------------
+# http://www.plainblack.com                     info@plainblack.com
+#------------------------------------------------------------------
+
+use FindBin;
+use strict;
+use lib "$FindBin::Bin/../../lib";
+use Test::More;
+use WebGUI::Test; # Must use this before any other WebGUI modules
+use WebGUI::Session;
+use Test::MockObject;
+use Test::MockObject::Extends;
+
+#----------------------------------------------------------------------------
+# Init
+my $session         = WebGUI::Test->session;
+
+
+#----------------------------------------------------------------------------
+# Tests
+
+plan tests => 4;        # Increment this number for each test you create
+
+my $sendmock = Test::MockObject->new( {} );
+$sendmock->set_isa('WebGUI::Mail::Send');
+$sendmock->set_true('addText', 'send');
+local *WebGUI::Mail::Send::create;
+$sendmock->fake_module('WebGUI::Mail::Send',
+    create => sub { return $sendmock },
+);
+
+my $getmock = Test::MockObject->new( {} );
+$getmock->set_isa('WebGUI::Mail::Get');
+# false for now.  use set_series later to add list of messages.
+$getmock->set_false('getNextMessage');
+$getmock->set_true('disconnect');
+local *WebGUI::Mail::Get::connect;
+$getmock->fake_module('WebGUI::Mail::Get',
+    connect => sub { return $getmock },
+);
+
+my $activity = Test::MockObject::Extends->new( 'WebGUI::Workflow::Activity::GetCsMail' );
+$activity->set_always('session', $session);
+$activity->set_always('getTTL', 60);
+$activity->set_always('COMPLETE', 'complete');
+my $parentAsset;
+$activity->mock('addPost', sub { $parentAsset = $_[1] } );
+
+my $cs_id    = 'MAILCS________________';
+my $post_id  = 'MAILCSPOST____________';
+my $cs2_id   = 'OTHERCS_______________';
+my $post2_id = 'OTHERCSPOST___________';
+
+my $csmock = Test::MockObject->new({
+    getMail => 1,
+    postGroupId => 7,
+    allowReplies => 1,
+});
+$csmock->set_isa('WebGUI::Asset::Wobject::Collaboration');
+$csmock->mock('get', sub {
+    my $self = shift;
+    if (@_) {
+        return $self->{$_[0]};
+    }
+    return $self;
+});
+$csmock->set_always('getId', $cs_id);
+
+my $postmock = Test::MockObject->new( {} );
+$postmock->set_isa('WebGUI::Asset::Post::Thread', 'WebGUI::Asset::Post');
+$postmock->set_always('getThread', $postmock);
+$postmock->set_always('getParent', $csmock);
+$postmock->set_always('getId', $post_id);
+
+my $cs2mock = Test::MockObject->new({});
+$cs2mock->set_isa('WebGUI::Asset::Wobject::Collaboration');
+$cs2mock->set_always('getId', $cs2_id);
+
+my $post2mock = Test::MockObject->new( {} );
+$post2mock->set_isa('WebGUI::Asset::Post::Thread', 'WebGUI::Asset::Post');
+$post2mock->set_always('getThread', $post2mock);
+$post2mock->set_always('getParent', $cs2mock);
+$post2mock->set_always('getId', $post2_id);
+
+{
+    $getmock->set_series('getNextMessage', {
+        from => 'admin@localhost',
+        parts => ['parts'],
+        subject => 'Subject',
+        messageId => 'Message Id',
+    });
+    $activity->execute($csmock);
+    is $parentAsset->getId, $cs_id, 'add as new thread to current cs if not reply';
+}
+
+{
+    # simulate asset not found
+    local *WebGUI::Asset::newByDynamicClass = sub {
+        return undef;
+    };
+    $getmock->set_series('getNextMessage', {
+        from => 'admin@localhost',
+        parts => ['parts'],
+        subject => 'Subject',
+        messageId => 'Message Id',
+        inReplyTo => 'cs-' . $post2_id . '@',
+    });
+    $activity->execute($csmock);
+    is $parentAsset->getId, $cs_id, 'add as new thread to current cs if reply to nonexistant post';
+}
+
+{
+    local *WebGUI::Asset::newByDynamicClass = sub {
+        return $post2mock;
+    };
+    $getmock->set_series('getNextMessage', {
+        from => 'admin@localhost',
+        parts => ['parts'],
+        subject => 'Subject',
+        messageId => 'Message Id',
+        inReplyTo => 'cs-' . $post2_id . '@',
+    });
+    $activity->execute($csmock);
+    is $parentAsset->getId, $cs_id, 'add as new thread to current cs if reply to post in another CS';
+}
+
+{
+    local *WebGUI::Asset::newByDynamicClass = sub {
+        return $postmock;
+    };
+    $getmock->set_series('getNextMessage', {
+        from => 'admin@localhost',
+        parts => ['parts'],
+        subject => 'Subject',
+        messageId => 'Message Id',
+        inReplyTo => 'cs-' . $post_id . '@',
+    });
+    $activity->execute($csmock);
+    is $parentAsset->getId, $post_id, 'add as reply to post if reply to post in current CS';
+}
+
+#----------------------------------------------------------------------------
+# Cleanup
+END {
+
+}
+#vim:ft=perl