--- a/js/tests/e4x/Regress/regress-308111.js
+++ b/js/tests/e4x/Regress/regress-308111.js
@@ -303,17 +303,16 @@ var xml = <prefs>
 <pref><name>layout.word_select.stop_at_punctuation</name></pref>
 <pref><name>browser.search.order.Yahoo</name></pref>
 <pref><name>middlemouse.paste</name></pref>
 <pref><name>font.name.sans-serif.zh-HK</name></pref>
 <pref><name>dom.disable_window_open_feature.toolbar</name></pref>
 <pref><name>dom.popup_maximum</name></pref>
 <pref><name>security.warn_entering_secure</name></pref>
 <pref><name>mousewheel.horizscroll.withaltkey.numlines</name></pref>
-<pref><name>javascript.allow.mailnews</name></pref>
 <pref><name>browser.tabs.warnOnCloseOther</name></pref>
 <pref><name>intl.accept_charsets</name></pref>
 <pref><name>font.name.monospace.x-central-euro</name></pref>
 <pref><name>alerts.height</name></pref>
 <pref><name>font.name-list.serif.x-tamil</name></pref>
 <pref><name>capability.policy.mailnews.SchemaLoader.onLoad</name></pref>
 <pref><name>font.size.variable.x-western</name></pref>
 <pref><name>keyword.URL</name></pref>

--- a/modules/libpref/src/init/all.js
+++ b/modules/libpref/src/init/all.js
@@ -532,17 +532,16 @@ pref("content.sink.pending_event_mode", 
 //   0 = openAllowed
 //   1 = openControlled
 //   2 = openAbused
 pref("privacy.popups.disable_from_plugins", 2);
 
 pref("dom.event.contextmenu.enabled",       true);
 
 pref("javascript.enabled",                  true);
-pref("javascript.allow.mailnews",           false);
 pref("javascript.options.strict",           false);
 pref("javascript.options.relimit",          false);
 pref("javascript.options.jit.content",      true);
 pref("javascript.options.jit.chrome",       true);
 // This preference limits the memory usage of javascript.
 // If you want to change these values for your device,
 // please find Bug 417052 comment 17 and Bug 456721
 // Comment 32.

--- a/testing/sisyphus/prefs/mail-user.js
+++ b/testing/sisyphus/prefs/mail-user.js
@@ -7,17 +7,16 @@ user_pref("capability.policy.trusted.sit
 user_pref("capability.principal.codebase.p0.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalBrowserWrite UniversalPreferencesRead UniversalBrowserRead");
 user_pref("capability.principal.codebase.p0.id", "http://test.mozilla.com");
 user_pref("capability.principal.codebase.p1.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalBrowserWrite UniversalPreferencesRead UniversalBrowserRead");
 user_pref("capability.principal.codebase.p1.id", "http://test.bclary.com");
 user_pref("dom.allow_scripts_to_close_windows", true);
 user_pref("dom.max_script_run_time", 0);
 user_pref("extensions.update.enabled", false);
 user_pref("extensions.update.notifyUser", false);
-user_pref("javascript.allow.mailnews", true);
 user_pref("mail.startup.enabledMailCheckOnce", false);
 user_pref("security.enable_java", false);
 user_pref("security.warn_submit_insecure", false);
 user_pref("signed.applets.codebase_principal_support", true);
 user_pref("mailnews.start_page.override_url", "http://test.mozilla.com/bin/install-extensions-1.html");
 user_pref("mailnews.start_page.url", "http://test.mozilla.com/bin/install-extensions-1.html");
 user_pref("mailnews.start_page.welcome_url", "http://test.mozilla.com/bin/install-extensions-1.html");
 user_pref("browser.warnOnQuit", false);

--- a/testing/sisyphus/prefs/public-user.js
+++ b/testing/sisyphus/prefs/public-user.js
@@ -11,17 +11,16 @@ user_pref("capability.principal.codebase
 user_pref("capability.principal.codebase.p1.id", "http://test.bclary.com");
 user_pref("dom.allow_scripts_to_close_windows", false);
 user_pref("dom.disable_move_resize", true);
 user_pref("dom.disable_open_during_load", true);
 user_pref("dom.disable_window_flip", true);
 user_pref("dom.disable_window_open_feature.status", true);
 user_pref("dom.max_script_run_time", 0);
 user_pref("dom.max_chrome_script_run_time", 0);
-user_pref("javascript.allow.mailnews", false);
 user_pref("javascript.options.showInConsole", true);
 user_pref("layout.css.report_errors", true);
 user_pref("security.enable_java", false);
 user_pref("security.warn_entering_secure", false);
 user_pref("security.warn_entering_weak", false);
 user_pref("security.warn_leaving_secure", false);
 user_pref("security.warn_submit_insecure", false);
 user_pref("security.warn_viewing_mixed", false);

--- a/testing/sisyphus/prefs/test-user.js
+++ b/testing/sisyphus/prefs/test-user.js
@@ -8,17 +8,16 @@ user_pref("capability.policy.trusted.sit
 user_pref("capability.principal.codebase.p0.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalBrowserWrite UniversalPreferencesRead UniversalBrowserRead");
 user_pref("capability.principal.codebase.p0.id", "http://test.mozilla.com");
 user_pref("capability.principal.codebase.p1.granted", "UniversalPreferencesWrite UniversalXPConnect UniversalBrowserWrite UniversalPreferencesRead UniversalBrowserRead");
 user_pref("capability.principal.codebase.p1.id", "http://test.bclary.com");
 user_pref("dom.allow_scripts_to_close_windows", true);
 user_pref("dom.disable_open_during_load", false);
 user_pref("dom.max_script_run_time", 0);
 user_pref("dom.max_chrome_script_run_time", 0);
-user_pref("javascript.allow.mailnews", true);
 user_pref("javascript.options.showInConsole", true);
 user_pref("layout.css.report_errors", true);
 user_pref("security.enable_java", false);
 user_pref("security.warn_entering_secure", false);
 user_pref("security.warn_entering_weak", false);
 user_pref("security.warn_leaving_secure", false);
 user_pref("security.warn_submit_insecure", false);
 user_pref("security.warn_viewing_mixed", false);