diff --git a/config/autoconf.mk.in b/config/autoconf.mk.in
--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -421,16 +421,17 @@ NSPR_CONFIG	= @NSPR_CONFIG@
 NSPR_CFLAGS	= @NSPR_CFLAGS@
 NSPR_LIBS	= @NSPR_LIBS@
 
 NSS_CONFIG	= @NSS_CONFIG@
 NSS_CFLAGS	= @NSS_CFLAGS@
 NSS_LIBS	= @NSS_LIBS@
 NSS_DEP_LIBS	= @NSS_DEP_LIBS@
 
+MOZ_NATIVE_MOZLDAP = @SYSTEM_MOZLDAP@
 LDAP_CFLAGS	= @LDAP_CFLAGS@
 LDAP_LIBS	= @LDAP_LIBS@
 XPCOM_GLUE_LDOPTS = @XPCOM_GLUE_LDOPTS@
 XPCOM_STANDALONE_GLUE_LDOPTS = @XPCOM_STANDALONE_GLUE_LDOPTS@
 MOZ_XPCOM_OBSOLETE_LIBS = @MOZ_XPCOM_OBSOLETE_LIBS@
 
 USE_DEPENDENT_LIBS = @USE_DEPENDENT_LIBS@
 
diff --git a/configure.in b/configure.in
--- a/configure.in
+++ b/configure.in
@@ -4936,16 +4936,34 @@ dnl ====================================
 dnl = LDAP
 dnl =========================================================
 MOZ_ARG_DISABLE_BOOL(ldap,
 [  --disable-ldap          Disable LDAP support],
     MOZ_LDAP_XPCOM=,
     MOZ_LDAP_XPCOM=1)
 
 dnl ========================================================
+dnl = If mozldap was not detected in the system, 
+dnl = use the one in the source tree (mozilla/directory/c-sdk)
+dnl ========================================================
+
+if test -n "$MOZ_LDAP_XPCOM"; then
+  MOZ_ARG_ENABLE_BOOL(system-mozldap,
+  [  --enable-system-mozldap  
+                          Use system installed mozldap (located with pkgconfig)],
+      SYSTEM_MOZLDAP=1 )
+
+  if test -n "$SYSTEM_MOZLDAP"; then
+      PKG_CHECK_MODULES(MOZLDAP, mozldap >= 6.0.6,
+        SYSTEM_MOZLDAP=1, SYSTEM_MOZLDAP=)
+  fi
+fi
+AC_SUBST(SYSTEM_MOZLDAP)
+
+dnl ========================================================
 dnl = Trademarked Branding 
 dnl ========================================================
 MOZ_ARG_ENABLE_BOOL(official-branding,
 [  --enable-official-branding Enable Official mozilla.org Branding
                           Do not distribute builds with
                           --enable-official-branding unless you have
                           permission to use trademarks per
                           http://www.mozilla.org/foundation/trademarks/ .],
@@ -7043,17 +7061,22 @@ if test "$MOZ_LDAP_XPCOM"; then
         if test -n "$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${DIST}/lib -lldap60 -lprldap60 -lldif60'
+        if test "$SYSTEM_MOZLDAP"; then
+            LDAP_LIBS="$MOZLDAP_LIBS"
+            LDAP_CFLAGS="$MOZLDAP_CFLAGS"
+        else
+            LDAP_LIBS='-L${DIST}/bin -L${DIST}/lib -lldap60 -lprldap60 -lldif60'
+        fi
     fi
 fi
 
 dnl ========================================================
 dnl =
 dnl = Maintainer debug option (no --enable equivalent)
 dnl =
 dnl ========================================================
@@ -7603,17 +7626,17 @@ fi
 AC_OUTPUT_SUBDIRS(mozilla)
 ac_configure_args="$_SUBDIR_CONFIG_ARGS"
 MOZ_BUILD_APP="$MOZ_BUILD_APP_CACHED"
 
 if test "$COMPILE_ENVIRONMENT"; then
 # if we're building the LDAP XPCOM component, we need to build 
 # the c-sdk first.  
 #
-if test "$MOZ_LDAP_XPCOM"; then
+if test "$MOZ_LDAP_XPCOM" -a -z "$SYSTEM_MOZLDAP" ; then
 
     # these subdirs may not yet have been created in the build tree.
     # don't use the "-p" switch to mkdir, since not all platforms have it
     #
     if test ! -d "directory"; then
         mkdir "directory"
     fi
     if test ! -d "directory/c-sdk"; then
diff --git a/mail/build.mk b/mail/build.mk
--- a/mail/build.mk
+++ b/mail/build.mk
@@ -47,17 +47,19 @@ ifdef MOZ_EXTENSIONS
 tier_app_dirs += extensions
 endif
 
 else # toplevel Makefile
 
 TIERS += app
 
 ifdef MOZ_LDAP_XPCOM
+ifndef MOZ_NATIVE_MOZLDAP
 tier_app_staticdirs += directory/c-sdk
+endif
 tier_app_dirs += directory/xpcom
 endif
 
 ifdef MOZ_COMPOSER
 tier_app_dirs += editor/ui
 endif
 
 ifdef MOZ_BRANDING_DIRECTORY
diff --git a/suite/build.mk b/suite/build.mk
--- a/suite/build.mk
+++ b/suite/build.mk
@@ -47,17 +47,19 @@ ifdef MOZ_EXTENSIONS
 tier_app_dirs += extensions
 endif
 
 else # toplevel Makefile
 
 TIERS += app
 
 ifdef MOZ_LDAP_XPCOM
+ifndef MOZ_NATIVE_MOZLDAP
 tier_app_staticdirs += directory/c-sdk
+endif
 tier_app_dirs += directory/xpcom
 endif
 
 ifdef MOZ_COMPOSER
 tier_app_dirs += editor/ui
 endif
 
 ifdef MOZ_BRANDING_DIRECTORY