--- a/mail/app/Makefile.in
+++ b/mail/app/Makefile.in
@@ -110,22 +110,16 @@ RCINCLUDE = splash.rc
 EXTRA_DEPS += $(PROGRAM).manifest
 ifndef GNU_CC
 RCFLAGS += -DMOZ_THUNDERBIRD -I$(srcdir)
 else
 RCFLAGS += -DMOZ_THUNDERBIRD --include-dir $(srcdir)
 endif
 endif
 
-ifeq ($(OS_ARCH),OS2)
-RESFILE=splashos2.res
-RCFLAGS += -DMOZ_THUNDERBIRD
-RCFLAGS += -DTHUNDERBIRD_ICO=\"$(DIST)/branding/thunderbird.ico\"
-endif
-
 include $(topsrcdir)/config/rules.mk
 
 ifeq ($(OS_ARCH),WINNT)
 
 $(RESFILE): embedded-icons
 
 #
 # Control the default heap size.
@@ -141,26 +135,26 @@ ifndef GNU_CC
 LDFLAGS += /HEAP:0x40000
 ifeq ($(OS_TEST),x86_64)
 # set stack to 2MB on x64 build.  See bug 582910                                
 LDFLAGS += -STACK:2097152
 endif
 endif
 endif
 
-ifneq (,$(filter-out OS2 WINNT,$(OS_ARCH)))
+ifneq ($(OS_ARCH),WINNT)
 libs::
 	cp -p $(MOZ_APP_NAME)$(BIN_SUFFIX) $(DIST)/bin/$(MOZ_APP_NAME)-bin$(BIN_SUFFIX)
 
 GARBAGE += $(addprefix $(DIST)/bin/defaults/pref/, all.js all-thunderbird.js channel-prefs.js mailnews.js)
-endif # ! OS 2 or WinNT
+endif # ! WinNT
 
 endif # LIBXUL_SDK
 
-ifneq (,$(filter windows os2,$(MOZ_WIDGET_TOOLKIT)))
+ifneq (,$(filter windows,$(MOZ_WIDGET_TOOLKIT)))
 ICON_SUFFIX=.ico
 
 DESKTOP_ICONS = \
 	abcardWindow \
 	addressbookWindow \
 	msgcomposeWindow \
 	$(NULL) 
 

deleted file mode 100644
index daae3a4b3faa2a539b9226a862d6cccef5f31086..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

deleted file mode 100644
index daae3a4b3faa2a539b9226a862d6cccef5f31086..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

deleted file mode 100644
index 374278747e94dbb3a7cd3c1d792072c9457e3561..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

deleted file mode 100644
--- a/mail/app/splashos2.rc
+++ /dev/null
@@ -1,23 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-#include <os2.h>
-
-// Splash screen dialog ID.
-#define IDD_SPLASH  100
-
-// Splash screen bitmap ID.
-#define IDB_SPLASH  101
-
-ICON 1 THUNDERBIRD_ICO
-
-DLGTEMPLATE IDD_SPLASH DISCARDABLE 
-BEGIN
-    DIALOG "", IDD_SPLASH, 0, 0, 390, 261, , FCF_BORDER
-    BEGIN
-    END
-END
-
-//BITMAP IDB_SPLASH "splash.bmp"

--- a/mail/branding/aurora/Makefile.in
+++ b/mail/branding/aurora/Makefile.in
@@ -33,19 +33,13 @@ endif
 ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
 	cp $(srcdir)/mailicon16.png  $(DIST)/branding/default16.png
 	cp $(srcdir)/mailicon22.png  $(DIST)/branding/default22.png
 	cp $(srcdir)/mailicon24.png  $(DIST)/branding/default24.png
 	cp $(srcdir)/mailicon32.png  $(DIST)/branding/default32.png
 	cp $(srcdir)/mailicon48.png  $(DIST)/branding/default48.png
 	cp $(srcdir)/mailicon256.png $(DIST)/branding/default256.png
 endif
-ifeq ($(OS_ARCH),OS2)
-	cp $(srcdir)/thunderbird-os2.ico   $(DIST)/branding/thunderbird.ico
-endif
 
 # Now sort out the branding specific icons
 ifeq ($(OS_ARCH),WINNT)
 	cp $(srcdir)/windows/messengerWindow.ico  $(DIST)/branding/messengerWindow.ico
 endif
-ifeq ($(OS_ARCH),OS2)
-	cp $(srcdir)/os2/messengerWindow.ico  $(DIST)/branding/messengerWindow.ico
-endif

deleted file mode 100644
index 6c3555877e35c212a6d92ad0c8bae53c1e6b70db..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

deleted file mode 100644
index 6c3555877e35c212a6d92ad0c8bae53c1e6b70db..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

--- a/mail/branding/nightly/Makefile.in
+++ b/mail/branding/nightly/Makefile.in
@@ -33,19 +33,13 @@ endif
 ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
 	cp $(srcdir)/mailicon16.png  $(DIST)/branding/default16.png
 	cp $(srcdir)/mailicon22.png  $(DIST)/branding/default22.png
 	cp $(srcdir)/mailicon24.png  $(DIST)/branding/default24.png
 	cp $(srcdir)/mailicon32.png  $(DIST)/branding/default32.png
 	cp $(srcdir)/mailicon48.png  $(DIST)/branding/default48.png
 	cp $(srcdir)/mailicon256.png $(DIST)/branding/default256.png
 endif
-ifeq ($(OS_ARCH),OS2)
-	cp $(srcdir)/thunderbird-os2.ico   $(DIST)/branding/thunderbird.ico
-endif
 
 # Now sort out the branding specific icons
 ifeq ($(OS_ARCH),WINNT)
 	cp $(srcdir)/windows/messengerWindow.ico  $(DIST)/branding/messengerWindow.ico
 endif
-ifeq ($(OS_ARCH),OS2)
-	cp $(srcdir)/os2/messengerWindow.ico  $(DIST)/branding/messengerWindow.ico
-endif

deleted file mode 100644
index ff6094cb7cafdb9b636fb17cc0baa13a452e1038..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

deleted file mode 100644
index ff6094cb7cafdb9b636fb17cc0baa13a452e1038..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
GIT binary patch
literal 0
Hc$@<O00001

--- a/mail/components/migration/src/nsSeamonkeyProfileMigrator.cpp
+++ b/mail/components/migration/src/nsSeamonkeyProfileMigrator.cpp
@@ -229,24 +229,16 @@ nsSeamonkeyProfileMigrator::FillProfileD
 
 #elif defined(XP_UNIX)
 #define NEW_FOLDER "seamonkey"
 #define EXTRA_PREPEND ".mozilla"
   fileLocator->Get(NS_UNIX_HOME_DIR, NS_GET_IID(nsIFile),
                    getter_AddRefs(seamonkeyData));
   NS_ENSURE_TRUE(seamonkeyData, NS_ERROR_FAILURE);
 
-#elif defined(XP_OS2)
-#define NEW_FOLDER "SeaMonkey"
-#define EXTRA_PREPEND "Mozilla"
-
-  fileLocator->Get(NS_OS2_HOME_DIR, NS_GET_IID(nsIFile),
-                   getter_AddRefs(seamonkeyData));
-  NS_ENSURE_TRUE(seamonkeyData, NS_ERROR_FAILURE);
-
 #else
   // On other OS just abort.
   return NS_ERROR_FAILURE;
 #endif
 
   nsCOMPtr<nsIFile> newSeamonkeyData;
   seamonkeyData->Clone(getter_AddRefs(newSeamonkeyData));
   NS_ENSURE_TRUE(newSeamonkeyData, NS_ERROR_FAILURE);

--- a/mail/components/preferences/preferences.xul
+++ b/mail/components/preferences/preferences.xul
@@ -22,19 +22,16 @@
 <!ENTITY % preferencesDTD SYSTEM "chrome://messenger/locale/preferences/preferences.dtd">
 %brandDTD;
 %preferencesDTD;
 ]>
 
 #ifdef XP_WIN
 #define USE_WIN_TITLE_STYLE
 #endif
-#ifdef XP_OS2
-#define USE_WIN_TITLE_STYLE
-#endif
 
 <prefwindow type="prefwindow"
             id="MailPreferences"
             windowtype="Mail:Preferences"
 #ifdef USE_WIN_TITLE_STYLE
             title="&prefWindow.titleWin;"
 #else
 #ifdef XP_UNIX

--- a/mail/configure.in
+++ b/mail/configure.in
@@ -11,17 +11,17 @@ AC_SUBST(MOZ_COMPOSER)
 AC_SUBST(THUNDERBIRD_VERSION)
 
 dnl Optional parts of the build.
 AC_SUBST(MOZ_MORK)
 if test "$MOZ_MORK"; then
   AC_DEFINE(MOZ_MORK)
   MORK_MODULE="MODULE(nsMorkModule)"
 fi
-if test "$OS_ARCH" != "WINNT" -a "$OS_ARCH" != "OS2"; then
+if test "$OS_ARCH" != "WINNT"; then
   MOZ_MOVEMAIL=1
   HAVE_MOVEMAIL=1
   AC_DEFINE(HAVE_MOVEMAIL)
 fi
 AC_SUBST(MOZ_MOVEMAIL)
 
 dnl Get other versions (for the calendar plugin)
 if test "$COMM_BUILD" = "1"; then
@@ -59,18 +59,16 @@ MOZ_ARG_DISABLE_BOOL(ldap,
 if test "$MOZ_LDAP_XPCOM"; then
     LDAP_CFLAGS='-I${DIST}/public/ldap'
     if test "$OS_ARCH" = "WINNT"; then
         if test -n "$GNU_CC"; then
             LDAP_LIBS='-L$(DIST)/lib -lnsldap32v60 -lnsldappr32v60 -lnsldif32v60'
         else
             LDAP_LIBS='$(DIST)/lib/$(LIB_PREFIX)nsldap32v60.${IMPORT_LIB_SUFFIX} $(DIST)/lib/$(LIB_PREFIX)nsldappr32v60.${IMPORT_LIB_SUFFIX} $(DIST)/lib/$(LIB_PREFIX)nsldif32v60.${IMPORT_LIB_SUFFIX}'
         fi
-    elif test "$OS_ARCH" = "OS2"; then
-            LDAP_LIBS='$(DIST)/lib/$(LIB_PREFIX)ldap60.${IMPORT_LIB_SUFFIX} $(DIST)/lib/$(LIB_PREFIX)prldap60.${IMPORT_LIB_SUFFIX} $(DIST)/lib/$(LIB_PREFIX)ldif60.${IMPORT_LIB_SUFFIX}'
     else
         LDAP_LIBS='-L${DIST}/bin -L${DIST}/lib -lldap60 -lprldap60 -lldif60'
     fi
 
     LDAP_MODULE="MODULE(nsLDAPProtocolModule)"
 fi
 
 AC_SUBST(MOZ_LDAP_XPCOM)

--- a/mail/installer/package-manifest.in
+++ b/mail/installer/package-manifest.in
@@ -122,39 +122,28 @@
 @BINPATH@/@MOZ_APP_NAME@
 #endif
 @BINPATH@/application.ini
 #ifdef MOZ_UPDATER
 @BINPATH@/update-settings.ini
 #endif
 @BINPATH@/blocklist.xml
 @BINPATH@/platform.ini
-#ifdef XP_OS2
-@BINPATH@/@DLL_PREFIX@mozsqlt3@DLL_SUFFIX@
-#else
 #ifndef MOZ_NATIVE_SQLITE
 #ifndef MOZ_FOLD_LIBS
 @BINPATH@/@DLL_PREFIX@mozsqlite3@DLL_SUFFIX@
 #endif
 #endif
-#endif
 #ifdef UNIX_BUT_NOT_MAC
 @BINPATH@/run-mozilla.sh
 #ifdef MOZ_UPDATER
 @BINPATH@/icons/*.png
 #endif
 #endif
 
-; [OS/2]
-#ifdef XP_OS2
-@BINPATH@/MozSounds.cmd
-@BINPATH@/*.xqs
-@BINPATH@/components/*.xqs
-#endif
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; Mail Specific Files
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 @BINPATH@/defaults/messenger/mailViews.dat
 @BINPATH@/defaults/profile/localstore.rdf
 @BINPATH@/defaults/profile/prefs.js
 @BINPATH@/defaults/profile/mimeTypes.rdf
 
@@ -198,19 +187,17 @@
 @BINPATH@/components/nsYouSendIt.js
 @BINPATH@/components/nsUbuntuOne.js
 @BINPATH@/components/nsBox.js
 @BINPATH@/components/nsAddrbook.manifest
 @BINPATH@/components/nsMailNewsCommandLineHandler.js
 @BINPATH@/components/nsNewsAutoCompleteSearch.js
 @BINPATH@/components/nsNewsAutoCompleteSearch.manifest
 @BINPATH@/components/services-crypto-component.xpt
-#ifndef XP_OS2
 @BINPATH@/components/shellservice.xpt
-#endif
 @BINPATH@/components/xpcom_base.xpt
 @BINPATH@/components/xpcom_system.xpt
 @BINPATH@/components/xpcom_components.xpt
 @BINPATH@/components/xpcom_ds.xpt
 @BINPATH@/components/xpcom_io.xpt
 @BINPATH@/components/xpcom_threads.xpt
 @BINPATH@/components/xpcom_xpti.xpt
 @BINPATH@/chrome/toolkit@JAREXT@
@@ -249,20 +236,18 @@
 @BINPATH@/MapiProxy.dll
 @BINPATH@/mozMapi32.dll
 @BINPATH@/components/mapihook.xpt
 #endif
 @BINPATH@/components/mailComponents.manifest
 @BINPATH@/components/mailContentHandler.js
 @BINPATH@/components/mailGlue.js
 @BINPATH@/components/nsMailDefaultHandler.js
-#ifndef XP_OS2
 @BINPATH@/components/nsSetDefaultMail.js
 @BINPATH@/components/shell.manifest
-#endif
 @BINPATH@/components/offlineStartup.js
 @BINPATH@/components/offlineStartup.manifest
 @BINPATH@/components/steelApplication.js
 @BINPATH@/components/steelApplication.manifest
 
 
 @BINPATH@/components/mdn-service.js
 @BINPATH@/components/mdn-service.manifest
@@ -792,24 +777,22 @@
 ; [Crash Reporter]
 ;
 #ifdef MOZ_CRASHREPORTER
 @BINPATH@/components/CrashService.manifest
 @BINPATH@/components/CrashService.js
 #ifdef XP_MACOSX
 @BINPATH@/crashreporter.app/
 #else
-#ifndef XP_OS2
 @BINPATH@/crashreporter@BIN_SUFFIX@
 @BINPATH@/crashreporter.ini
 #ifdef XP_UNIX
 @BINPATH@/Throbber-small.gif
 #endif
 #endif
-#endif
 #ifdef MOZ_CRASHREPORTER_INJECTOR
 @BINPATH@/breakpadinjector.dll
 #endif
 #endif
 
 ; GNOME hooks
 #ifdef MOZ_ENABLE_GNOME_COMPONENT
 @BINPATH@/components/@DLL_PREFIX@mozgnome@DLL_SUFFIX@

--- a/mail/installer/removed-files.in
+++ b/mail/installer/removed-files.in
@@ -101,21 +101,17 @@ components/walletpreview.xpt
 components/@DLL_PREFIX@walletviewers@DLL_SUFFIX@
 #ifndef MOZ_WEBSERVICES
   components/websrvcs.xpt
 #endif
 #ifdef XP_MACOSX
   components/widget_mac.xpt
 #endif
 components/@DLL_PREFIX@xpcom_compat_c@DLL_SUFFIX@
-#ifdef XP_OS2
-  components/@DLL_PREFIX@xpcomcor@DLL_SUFFIX@
-#else
-  components/@DLL_PREFIX@xpcom_core@DLL_SUFFIX@
-#endif
+components/@DLL_PREFIX@xpcom_core@DLL_SUFFIX@
 components/xpcom_obsolete.xpt
 components/xpinstall.xpt
 components/@DLL_PREFIX@xpinstal@DLL_SUFFIX@
 components/@DLL_PREFIX@xpinstall@DLL_SUFFIX@
 components/xpti.dat
 components/xptitemp.dat
 components/myspell/en-US.dic
 components/myspell/en-US.aff
@@ -806,24 +802,20 @@ components/@DLL_PREFIX@import@DLL_SUFFIX
 components/@DLL_PREFIX@intlapp@DLL_SUFFIX@
 components/@DLL_PREFIX@jar50@DLL_SUFFIX@
 #ifndef XP_WIN
   components/@DLL_PREFIX@jsd@DLL_SUFFIX@
 #else
   components/@DLL_PREFIX@jsd3250@DLL_SUFFIX@
 #endif
 components/@DLL_PREFIX@mail@DLL_SUFFIX@
-#ifdef XP_OS2
+#ifdef XP_WIN
   components/@DLL_PREFIX@mailcmp@DLL_SUFFIX@
-#else
-  #ifdef XP_WIN
-    components/@DLL_PREFIX@mailcmp@DLL_SUFFIX@
-  #endif
-  components/@DLL_PREFIX@mailcomps@DLL_SUFFIX@
 #endif
+components/@DLL_PREFIX@mailcomps@DLL_SUFFIX@
 components/@DLL_PREFIX@mork@DLL_SUFFIX@
 components/@DLL_PREFIX@mozfind@DLL_SUFFIX@
 components/@DLL_PREFIX@mozldap@DLL_SUFFIX@
 components/@DLL_PREFIX@msgMapi@DLL_SUFFIX@
 components/@DLL_PREFIX@msgsmime@DLL_SUFFIX@
 components/@DLL_PREFIX@necko@DLL_SUFFIX@
 #ifdef XP_WIN
   components/@DLL_PREFIX@appshell@DLL_SUFFIX@