diff --git a/mailnews/base/content/msgAccountCentral.xul b/mailnews/base/content/msgAccountCentral.xul
index 70c2209f30..c1a43b0358 100644
--- a/mailnews/base/content/msgAccountCentral.xul
+++ b/mailnews/base/content/msgAccountCentral.xul
@@ -173,11 +173,6 @@
                  value="&emailSectionHdr.label;"
                  chromedir="&locale.dir;"
                  onclick="CreateNewAccountTB('mail');"/>
-          <label id="CreateAccountChat"
-                 class="acctCentralNewAcctText acctCentralLinkText"
-                 value="&chat.label;"
-                 chromedir="&locale.dir;"
-                 onclick="openIMAccountWizard();"/>
           <label id="CreateAccountNewsgroups"
                  class="acctCentralNewAcctText acctCentralLinkText"
                  value="&newsSectionHdr.label;"
diff --git a/mailnews/base/prefs/content/AccountManager.js b/mailnews/base/prefs/content/AccountManager.js
index 81fb115def..5de98ecd00 100644
--- a/mailnews/base/prefs/content/AccountManager.js
+++ b/mailnews/base/prefs/content/AccountManager.js
@@ -899,9 +899,6 @@ function updateButtons(tree, account) {
  * Called only by Thunderbird.
  */
 function initAccountActionsButtons(menupopup) {
-  if (!Services.prefs.getBoolPref("mail.chat.enabled"))
-    document.getElementById("accountActionsAddIMAccount").hidden = true;
-
   updateItems(
     document.getElementById("accounttree"),
     getCurrentAccount(),
@@ -1486,9 +1483,6 @@ var gAccountTree = {
       try {
         server = account.incomingServer;
 
-        if (server.type == "im" && !Services.prefs.getBoolPref("mail.chat.enabled"))
-          continue;
-
         accountName = server.prettyName;
 
         // Now add our panels.
diff --git a/mailnews/base/prefs/content/removeAccount.js b/mailnews/base/prefs/content/removeAccount.js
index 350a0a0659..77bbe58d5d 100644
--- a/mailnews/base/prefs/content/removeAccount.js
+++ b/mailnews/base/prefs/content/removeAccount.js
@@ -39,12 +39,6 @@ function onLoad(event) {
     document.getElementById("removeDataPossibility").collapsed = true;
   }
 
-  if (gServer.type == "im") {
-    let dataCheckbox = document.getElementById("removeData");
-    dataCheckbox.label = dataCheckbox.getAttribute("labelChat");
-    dataCheckbox.accessKey = dataCheckbox.getAttribute("accesskeyChat");
-  }
-
   enableRemove();
   window.sizeToContent();
 }
@@ -80,8 +74,6 @@ function showInfo() {
   // TODO: bug 1238271, this should use showFor attributes if possible.
   if (gServer.type == "imap" || gServer.type == "nntp") {
     document.getElementById("serverAccount").collapsed = false;
-  } else if (gServer.type == "im") {
-    document.getElementById("chatAccount").collapsed = false;
   } else {
     document.getElementById("localAccount").collapsed = false;
   }
diff --git a/mailnews/base/prefs/content/removeAccount.xul b/mailnews/base/prefs/content/removeAccount.xul
index 371262a11c..c1d565973d 100644
--- a/mailnews/base/prefs/content/removeAccount.xul
+++ b/mailnews/base/prefs/content/removeAccount.xul
@@ -46,10 +46,8 @@
       <vbox id="removeDataPossibility" collapsed="false">
       <checkbox id="removeData"
                 label="&removeData.label;"
-                labelChat="&removeData.label;"
                 checked="false"
                 accesskey="&removeData.accesskey;"
-                accesskeyChat="&removeData.accesskey;"
                 oncommand="enableRemove();"/>
       <vbox class="indent" collapsed="true">
         <description id="localAccount" collapsed="true">
@@ -58,9 +56,6 @@
         <description id="serverAccount" collapsed="true">
           &removeDataServerAccount.desc;
         </description>
-        <description id="chatAccount" collapsed="true">
-          &removeDataLocalAccount.desc;
-        </description>
         <hbox align="center">
           <button id="showLocalDirectory"
                   label="&showData.label;"
diff --git a/mailnews/base/src/nsMessengerOSXIntegration.mm b/mailnews/base/src/nsMessengerOSXIntegration.mm
index 286c760440..280bdf433d 100644
--- a/mailnews/base/src/nsMessengerOSXIntegration.mm
+++ b/mailnews/base/src/nsMessengerOSXIntegration.mm
@@ -51,11 +51,8 @@
 #include <Carbon/Carbon.h>
 #import <Cocoa/Cocoa.h>
 
-#define kChatEnabledPref "mail.chat.enabled"
 #define kBiffAnimateDockIconPref "mail.biff.animate_dock_icon"
 #define kMaxDisplayCount 10
-#define kNewChatMessageTopic "new-directed-incoming-message"
-#define kUnreadImCountChangedTopic "unread-im-count-changed"
 
 using namespace mozilla::mailnews;
 
@@ -162,7 +159,6 @@ nsMessengerOSXIntegration::nsMessengerOSXIntegration()
   mBiffStateAtom = MsgGetAtom("BiffState");
   mNewMailReceivedAtom = MsgGetAtom("NewMailReceived");
   mUnreadTotal = 0;
-  mUnreadChat = 0;
 }
 
 nsMessengerOSXIntegration::~nsMessengerOSXIntegration()
@@ -231,14 +227,7 @@ nsMessengerOSXIntegration::Observe(nsISupports* aSubject, const char* aTopic, co
     if (NS_SUCCEEDED(rv)) {
       observerService->RemoveObserver(this, "mail-startup-done");
 
-      bool chatEnabled = false;
       nsCOMPtr<nsIPrefBranch> pref(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
-      if (NS_SUCCEEDED(rv))
-        rv = pref->GetBoolPref(kChatEnabledPref, &chatEnabled);
-      if (NS_SUCCEEDED(rv) && chatEnabled) {
-        observerService->AddObserver(this, kNewChatMessageTopic, false);
-        observerService->AddObserver(this, kUnreadImCountChangedTopic, false);
-      }
     }
 
     // Register with the new mail service for changes to the unread message count
@@ -260,22 +249,11 @@ nsMessengerOSXIntegration::Observe(nsISupports* aSubject, const char* aTopic, co
     return mailSession->AddFolderListener(this, nsIFolderListener::boolPropertyChanged | nsIFolderListener::intPropertyChanged);
   }
 
-  if (!strcmp(aTopic, kNewChatMessageTopic)) {
-    // We don't have to bother about checking if the window is already focused
-    // before attempting to bounce the dock icon, as BounceDockIcon is
-    // implemented by a getAttention call which won't do anything if the window
-    // requesting attention is already focused.
-    return BounceDockIcon();
-  }
-
   if (!strcmp(aTopic, kUnreadImCountChangedTopic)) {
     nsresult rv;
     nsCOMPtr<nsISupportsPRInt32> unreadCount = do_QueryInterface(aSubject, &rv);
     NS_ENSURE_SUCCESS(rv, rv);
 
-    rv = unreadCount->GetData(&mUnreadChat);
-    NS_ENSURE_SUCCESS(rv, rv);
-
     return BadgeDockIcon();
   }
 
@@ -515,7 +493,7 @@ nsMessengerOSXIntegration::BadgeDockIcon()
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
 
-  int32_t unreadCount = mUnreadTotal + mUnreadChat;
+  int32_t unreadCount = mUnreadTotal;
   // If count is less than one, we should restore the original dock icon.
   if (unreadCount < 1)
   {
diff --git a/mailnews/base/src/nsStatusBarBiffManager.cpp b/mailnews/base/src/nsStatusBarBiffManager.cpp
index 49d9bfb521..27f393986d 100644
--- a/mailnews/base/src/nsStatusBarBiffManager.cpp
+++ b/mailnews/base/src/nsStatusBarBiffManager.cpp
@@ -40,15 +40,12 @@ nsStatusBarBiffManager::~nsStatusBarBiffManager()
 }
 
 #define NEW_MAIL_PREF_BRANCH             "mail.biff."
-#define CHAT_PREF_BRANCH                 "mail.chat."
 #define FEED_PREF_BRANCH                 "mail.feed."
 #define PREF_PLAY_SOUND                  "play_sound"
 #define PREF_SOUND_URL                   "play_sound.url"
 #define PREF_SOUND_TYPE                  "play_sound.type"
 #define SYSTEM_SOUND_TYPE 0
 #define CUSTOM_SOUND_TYPE 1
-#define PREF_CHAT_ENABLED                "mail.chat.enabled"
-#define PLAY_CHAT_NOTIFICATION_SOUND     "play-chat-notification-sound"
 
 nsresult nsStatusBarBiffManager::Init()
 {
@@ -67,16 +64,6 @@ nsresult nsStatusBarBiffManager::Init()
   nsCOMPtr<nsIPrefBranch> pref(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
   NS_ENSURE_SUCCESS(rv, rv);
 
-  bool chatEnabled = false;
-  if (NS_SUCCEEDED(rv))
-    rv = pref->GetBoolPref(PREF_CHAT_ENABLED, &chatEnabled);
-  if (NS_SUCCEEDED(rv) && chatEnabled) {
-    nsCOMPtr<nsIObserverService> observerService =
-      mozilla::services::GetObserverService();
-    if (observerService)
-      observerService->AddObserver(this, PLAY_CHAT_NOTIFICATION_SOUND, false);
-  }
-
   mInitialized = true;
   return NS_OK;
 }
@@ -237,7 +224,7 @@ nsStatusBarBiffManager::Observe(nsISupports *aSubject,
                                 const char *aTopic,
                                 const char16_t *aData)
 {
-  return PlayBiffSound(CHAT_PREF_BRANCH);
+  return NS_OK;
 }
 
 // nsIStatusBarBiffManager method....
diff --git a/mailnews/extensions/mdn/src/mdn-service.js b/mailnews/extensions/mdn/src/mdn-service.js
index 32e1cbde14..69f5572740 100644
--- a/mailnews/extensions/mdn/src/mdn-service.js
+++ b/mailnews/extensions/mdn/src/mdn-service.js
@@ -11,9 +11,9 @@ MDNService.prototype = {
   name: "mdn",
   chromePackageName: "messenger",
   showPanel: function(server) {
-    // don't show the panel for news, rss, im or local accounts
+    // don't show the panel for news, rss, or local accounts
     return (server.type != "nntp" && server.type != "rss" &&
-            server.type != "im" && server.type != "none");
+            server.type != "none");
   },
 
   QueryInterface: XPCOMUtils.generateQI([Components.interfaces.nsIMsgAccountManagerExtension]),
diff --git a/mailnews/extensions/smime/src/smime-service.js b/mailnews/extensions/smime/src/smime-service.js
index 9fa618fd6d..2c84192dd3 100644
--- a/mailnews/extensions/smime/src/smime-service.js
+++ b/mailnews/extensions/smime/src/smime-service.js
@@ -13,7 +13,7 @@ SMIMEService.prototype = {
   showPanel: function(server) {
     // don't show the panel for news, rss, or local accounts
     return (server.type != "nntp" && server.type != "rss" &&
-            server.type != "im" && server.type != "none");
+            server.type != "none");
   },
 
   QueryInterface: XPCOMUtils.generateQI([Components.interfaces.nsIMsgAccountManagerExtension]),