diff --git a/data/org.gnome.evolution.mail.gschema.xml.in b/data/org.gnome.evolution.mail.gschema.xml.in
index 3dcb39a15a..a6b4d56597 100644
--- a/data/org.gnome.evolution.mail.gschema.xml.in
+++ b/data/org.gnome.evolution.mail.gschema.xml.in
@@ -942,6 +942,11 @@
       <_summary>Show unread count in folder tree</_summary>
       <_description>Show unread count beside the folder name in the folder tree.</_description>
     </key>
+    <key name="show-insecure-parts" type="b">
+      <default>false</default>
+      <_summary>Show insecure parts by default</_summary>
+      <_description>Set whether not signed/encrypted parts beside signed/encrypted parts should be shown after mail open. The default is to hide these possibly insecure parts.</_description>
+    </key>
 
     <!-- The following keys are deprecated. -->
 
diff --git a/src/em-format/e-mail-formatter-utils.c b/src/em-format/e-mail-formatter-utils.c
index 4b89c8bd5a..0440e89d51 100644
--- a/src/em-format/e-mail-formatter-utils.c
+++ b/src/em-format/e-mail-formatter-utils.c
@@ -699,6 +699,8 @@ e_mail_formatter_format_security_header (EMailFormatter *formatter,
 
 		if (tmp->len > 0) {
 			if (is_partial && context && context->mode == E_MAIL_FORMATTER_MODE_NORMAL) {
+				GSettings *settings;
+				gboolean show_parts;
 				gint icon_width, icon_height;
 				gchar *escaped;
 
@@ -711,14 +713,18 @@ e_mail_formatter_format_security_header (EMailFormatter *formatter,
 				g_string_assign (tmp, escaped);
 				g_free (escaped);
 
+				settings = e_util_ref_settings ("org.gnome.evolution.mail");
+				show_parts = g_settings_get_boolean (settings, "show-insecure-parts");
+				g_object_unref (settings);
+
 				e_util_markup_append_escaped (tmp,
 					"&nbsp;&nbsp;&nbsp; (<img src=\"gtk-stock://dialog-warning?size=%d\" width=\"%dpx\" height=\"%dpx\" style=\"vertical-align:middle;\"/>&nbsp;"
-					"<a class=\"manage-insecure-parts\" id=\"show:%s\" value=\"%s\" style=\"cursor:pointer;\">%s</a>"
-					"<a class=\"manage-insecure-parts\" id=\"hide:%s\" value=\"%s\" style=\"cursor:pointer;\" hidden>%s</a>"
+					"<a class=\"manage-insecure-parts\" id=\"show:%s\" value=\"%s\" style=\"cursor:pointer;\"%s>%s</a>"
+					"<a class=\"manage-insecure-parts\" id=\"hide:%s\" value=\"%s\" style=\"cursor:pointer;\"%s>%s</a>"
 					")",
 					GTK_ICON_SIZE_BUTTON, icon_width, icon_height,
-					part_id_prefix, part_id_prefix, _("Show parts not being secured"),
-					part_id_prefix, part_id_prefix, _("Hide parts not being secured"));
+					part_id_prefix, part_id_prefix, show_parts ? " hidden" : "", _("Show parts not being secured"),
+					part_id_prefix, part_id_prefix, show_parts ? "" : " hidden", _("Hide parts not being secured"));
 
 				flags |= E_MAIL_FORMATTER_HEADER_FLAG_HTML;
 			}
diff --git a/src/mail/e-mail-display.c b/src/mail/e-mail-display.c
index 3ee587ca04..6dc2334e37 100644
--- a/src/mail/e-mail-display.c
+++ b/src/mail/e-mail-display.c
@@ -1470,7 +1470,8 @@ mail_display_content_loaded_cb (EWebView *web_view,
 			g_clear_object (&part);
 		}
 
-		if (mail_display->priv->has_secured_parts) {
+		if (mail_display->priv->has_secured_parts &&
+		    mail_display->priv->skip_insecure_parts) {
 			GSList *link;
 
 			for (link = mail_display->priv->insecure_part_ids; link; link = g_slist_next (link)) {
@@ -2796,6 +2797,7 @@ e_mail_display_init (EMailDisplay *display)
 	GtkUIManager *ui_manager;
 	GtkActionGroup *actions;
 	GList *acts_list, *link;
+	GSettings *settings;
 
 	display->priv = E_MAIL_DISPLAY_GET_PRIVATE (display);
 
@@ -2805,7 +2807,10 @@ e_mail_display_init (EMailDisplay *display)
 	display->priv->attachment_inline_group = gtk_action_group_new ("e-mail-display-attachment-inline");
 	display->priv->attachment_accel_action_group = gtk_action_group_new ("e-mail-display-attachment-accel");
 	display->priv->attachment_accel_group = gtk_accel_group_new ();
-	display->priv->skip_insecure_parts = TRUE;
+
+	settings = e_util_ref_settings ("org.gnome.evolution.mail");
+	display->priv->skip_insecure_parts = !g_settings_get_boolean (settings, "show-insecure-parts");
+	g_object_unref (settings);
 
 	gtk_action_group_add_actions (
 		display->priv->attachment_inline_group, attachment_inline_entries,
@@ -3118,6 +3123,7 @@ void
 e_mail_display_set_part_list (EMailDisplay *display,
                               EMailPartList *part_list)
 {
+	GSettings *settings;
 	GSList *insecure_part_ids = NULL;
 	gboolean has_secured_parts = FALSE;
 
@@ -3180,7 +3186,10 @@ e_mail_display_set_part_list (EMailDisplay *display,
 	g_slist_free_full (display->priv->insecure_part_ids, g_free);
 	display->priv->insecure_part_ids = insecure_part_ids;
 	display->priv->has_secured_parts = has_secured_parts;
-	display->priv->skip_insecure_parts = TRUE;
+
+	settings = e_util_ref_settings ("org.gnome.evolution.mail");
+	display->priv->skip_insecure_parts = !g_settings_get_boolean (settings, "show-insecure-parts");
+	g_object_unref (settings);
 
 	g_object_notify (G_OBJECT (display), "part-list");
 }