diff --git a/plugins/base/smtp.go b/plugins/base/smtp.go
index 50a2fd0..40967dc 100644
--- a/plugins/base/smtp.go
+++ b/plugins/base/smtp.go
@@ -172,6 +172,9 @@ func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
 	}
 
 	h.Set("Message-Id", msg.MessageID)
+	if msg.MessageID == "" {
+		panic(fmt.Errorf("Attempting to send message without message ID"))
+	}
 
 	mw, err := mail.CreateWriter(w, h)
 	if err != nil {
diff --git a/themes/alps/compose.html b/themes/alps/compose.html
index f4b7b9a..a8b6815 100644
--- a/themes/alps/compose.html
+++ b/themes/alps/compose.html
@@ -9,8 +9,8 @@
     <main class="create-update">
 
       <form method="post" enctype="multipart/form-data">
-        <input type="hidden" name="message_id" value="{{.Message.InReplyTo}}">
-        <input type="hidden" name="in_reply_to" value="{{.Message.MessageID}}">
+        <input type="hidden" name="message_id" value="{{.Message.MessageID}}">
+        <input type="hidden" name="in_reply_to" value="{{.Message.InReplyTo}}">
 
         <div class="headers no-js">
           <label>From</label>