[backend] Gestion de la limite d'envoi d'emails de Mailjet (50)

backend/models/MailForm.php

                 'TextPart' => $this->message.$messageAutoText,
                 'HTMLPart' => nl2br($this->message).$messageAutoHtml
             ] ;
+
+            if(count($body['Messages']) == 50) {
+                $response = $mj->post(\Mailjet\Resources::$Email, ['body' => $body]);
+                $body['Messages'] = [] ;
+            }
+        }
+
+        if(count($body['Messages']) > 0) {
+            $response = $mj->post(\Mailjet\Resources::$Email, ['body' => $body]);
         }
         
         $response = $mj->post(\Mailjet\Resources::$Email, ['body' => $body]);