diff --git a/apps/maarch_entreprise/definition_mail_categories.php b/apps/maarch_entreprise/definition_mail_categories.php
index 06cb1843353442541a3b4f69cb4fa023789ac4c3..c0f8fcfa1af07b35e4e4e78972e7eb04834d4d27 100644
--- a/apps/maarch_entreprise/definition_mail_categories.php
+++ b/apps/maarch_entreprise/definition_mail_categories.php
@@ -122,7 +122,7 @@ $_ENV['categories']['incoming']['nature_id'] = array (
     'label' => _NATURE,
     'table' => 'coll_ext',
     'img' => 'envelope',
-    'modify' => true,
+    'modify' => false,
     'form_show' => 'select'
 );
 $_ENV['categories']['incoming']['reference_number'] = array (
@@ -310,7 +310,7 @@ $_ENV['categories']['outgoing']['nature_id'] = array (
     'label' => _NATURE,
     'table' => 'coll_ext',
     'img' => 'envelope',
-    'modify' => true,
+    'modify' => false,
     'form_show' => 'select'
 );
 $_ENV['categories']['outgoing']['reference_number'] = array (
@@ -440,7 +440,7 @@ $_ENV['categories']['internal']['nature_id'] = array (
     'label' => _NATURE,
     'table' => 'coll_ext',
     'img' => 'envelope',
-    'modify' => true,
+    'modify' => false,
     'form_show' => 'select'
 );
 $_ENV['categories']['internal']['reference_number'] = array (
diff --git a/apps/maarch_entreprise/indexing_searching/details.php b/apps/maarch_entreprise/indexing_searching/details.php
index 9ebe5e95e46103e04549143b10a50de2baa21282..87ec053ba33d985514e834f6513d5d9cb5a3f36d 100755
--- a/apps/maarch_entreprise/indexing_searching/details.php
+++ b/apps/maarch_entreprise/indexing_searching/details.php
@@ -947,8 +947,6 @@ if ((!empty($_SESSION['error']) && ! ($_SESSION['indexation'] ))  )
                                         echo 'onchange="change_doctype_details(this.options[this.options.selectedIndex].value, \''.$_SESSION['config']['businessappurl'].'index.php?display=true&dir=indexing_searching&page=change_doctype_details\' , \''._DOCTYPE.' '._MISSING.'\');"';
                                     } else if ($key == 'priority') {
                                         echo 'onchange="updateProcessDate(\'' . $_SESSION['config']['businessappurl'] . 'index.php?display=true&dir=indexing_searching&page=update_process_date\', ' . $s_id . ')"';
-                                    } else if ($key == 'nature_id') {
-                                        echo 'disabled style="background-color : #e6e6e6;"';
                                     }
                                     ?>
                                     >