diff --git a/docs/configuration.md b/docs/configuration.md
index cb4f2bb..6918354 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -213,6 +213,15 @@ Make sure to do the necessary [port forwarding](https://portforward.com/) and ad
 **Default:** `!`  
 Prefix for bot commands
 
+#### reactOnSeen
+**Default:** `off`  
+If enabled, the bot will react to messages sent to it with the emoji defined in `reactOnSeenEmoji`
+
+#### reactOnSeenEmoji
+**Default:** `📨`  
+The emoji that the bot will react with when it sees a message.  Requires `reactOnSeen` to be enabled.  
+Must be pasted in the config file as the Emoji representation and not as a unicode codepoint. 
+
 #### relaySmallAttachmentsAsAttachments
 **Default:** `off`  
 If enabled, small attachments from users are sent as real attachments rather than links in modmail threads.
diff --git a/src/config.js b/src/config.js
index a2e3beb..769366e 100644
--- a/src/config.js
+++ b/src/config.js
@@ -121,6 +121,9 @@ const defaultConfig = {
   "knex": null,
 
   "logDir": path.join(__dirname, '..', 'logs'),
+
+  "reactOnSeen": false,
+  "reactOnSeenEmoji": "\uD83D\uDCE8",
 };
 
 // Load config values from environment variables
diff --git a/src/data/Thread.js b/src/data/Thread.js
index 23e9e4a..113eacb 100644
--- a/src/data/Thread.js
+++ b/src/data/Thread.js
@@ -163,6 +163,11 @@ class Thread {
       dm_message_id: msg.id
     });
 
+    if (config.reactOnSeen)
+    {
+        await msg.addReaction(config.reactOnSeenEmoji)
+    }
+
     if (this.scheduled_close_at) {
       await this.cancelScheduledClose();
       await this.postSystemMessage(`<@!${this.scheduled_close_id}> Thread that was scheduled to be closed got a new reply. Cancelling.`);