diff --git a/src/K2 b/src/K2
index 8402a7b47..c2138a36f 160000
--- a/src/K2
+++ b/src/K2
@@ -1 +1 @@
-Subproject commit 8402a7b4728a77b0ba5b2dacbb104363bb728282
+Subproject commit c2138a36f65bec707c834fea8281abae6059dddb
diff --git a/src/flux/tasks/send-draft-task.es6 b/src/flux/tasks/send-draft-task.es6
index ba939d62b..9e930f3b5 100644
--- a/src/flux/tasks/send-draft-task.es6
+++ b/src/flux/tasks/send-draft-task.es6
@@ -87,7 +87,8 @@ export default class SendDraftTask extends BaseDraftTask {
 
     // Sending individual bodies for too many participants can cause us
     // to hit the smtp rate limit.
-    if (this.draft.participants({includeFrom: false, includeBcc: true}).length > 10) {
+    const participants = this.draft.participants({includeFrom: false, includeBcc: true})
+    if (participants.length === 1 || participants.length > 10) {
       return false;
     }