diff --git a/modules/smtp/actions.php b/modules/smtp/actions.php
index 9a9cd1669..dc9e99cbb 100644
--- a/modules/smtp/actions.php
+++ b/modules/smtp/actions.php
@@ -36,6 +36,16 @@ switch (post('op')) {
         }
 
         $_SESSION['infos'][] = tr('Informazioni salvate correttamente!');
+        
+        //validazione indirizzo email mittente.
+        $check_email = Validate::isValidEmail($post['from_address'],1,1);
+        //print_r($check_email);
+        //exit();
+        //se $check_email non è null, l'indirizzo email è settato e la riposta è negativa --> mostro il messaggio di avviso.
+        if ((!is_null($check_email)) and (!$check_email->smtp_check) and (!empty($post['from_address']))){
+            $_SESSION['errors'][] = tr('Attenzione questo indirizzo non sembra essere valido: ').$post['from_address'];
+        }
+
 
         break;
 
diff --git a/modules/smtp/add.php b/modules/smtp/add.php
index ba8a7affe..9724ec638 100644
--- a/modules/smtp/add.php
+++ b/modules/smtp/add.php
@@ -18,7 +18,7 @@ include_once __DIR__.'/../../core.php';
 		</div>
 
 		<div class="col-md-6">
-			{[ "type": "email", "label": "<?php echo tr('Email mittente'); ?>", "name": "from_address" ]}
+			{[ "type": "email", "label": "<?php echo tr('Email mittente'); ?>", "name": "from_address", "required": 1 ]}
 		</div>
     </div>
 
diff --git a/modules/smtp/edit.php b/modules/smtp/edit.php
index cf64baa38..3472e7478 100644
--- a/modules/smtp/edit.php
+++ b/modules/smtp/edit.php
@@ -34,7 +34,7 @@ include_once __DIR__.'/../../core.php';
                 </div>
 
                 <div class="col-md-6">
-                    {[ "type": "email", "label": "<?php echo tr('Email mittente'); ?>", "name": "from_address", "value": "$from_address$" ]}
+                    {[ "type": "email", "label": "<?php echo tr('Email mittente'); ?>", "name": "from_address", "value": "$from_address$", "required": 1 ]}
                 </div>
             </div>
 
diff --git a/src/Validate.php b/src/Validate.php
new file mode 100644
index 000000000..0ca98933a
--- /dev/null
+++ b/src/Validate.php
@@ -0,0 +1,94 @@
+<?php
+
+/**
+ * Classe per la gestione delle funzioni VALIDATE richiamabili del progetto.
+ *
+ * @since 2.4
+ */
+class VALIDATE
+{
+    /**
+     * Controlla se l'email inserita è valida.
+     *
+     * @param string $email
+     * @param bool $format
+     * @param bool $smtp
+     *
+     * @return object
+     */
+    public static function isValidEmail($email, $format = 1, $smtp = 0)
+    {
+
+    	$access_key = Settings::get('apilayer API key');
+
+    	/*$data = (object) [
+		    'format_valid' => NULL,
+		    'mx_found' => NULL,
+		    'smtp_check' => NULL,
+		];*/
+
+	    if ((!empty($email)) and (!empty($access_key))){
+
+			$ch = curl_init();
+
+			$qs = "&email=" . urlencode($email);
+			$qs .=  "&smtp=$smtp";
+			$qs .= "&format=$format";
+
+			$url = "http://apilayer.net/api/check?access_key=$access_key" . $qs;
+			curl_setopt($ch, CURLOPT_URL, $url);
+			curl_setopt($ch, CURLOPT_HEADER, 0);
+			curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+			
+
+			$data = json_decode(curl_exec($ch));
+			curl_close($ch);
+			
+			/*se la riposta è null verficando il formato, il record mx o il server smtp imposto a false*/
+			if (($data->format_valid==null)and($format))
+				$data->format_valid = 0;
+
+			if (($data->mx_found==null)and($smtp))
+				$data->mx_found = 0;
+
+			if (($data->smtp_check==null)and($smtp))
+				$data->smtp_check = 0;
+
+			
+			/*controllo o meno smtp 
+			if ($data->smtp_check==false)
+				$data->smtp_check = 0;
+
+			if ($data->mx_found==false)
+				$data->mx_found = 0;
+			*/
+			/* --- */
+
+			/*echo "format_valid: ".$data->format_valid; 
+			echo "<br>\n";
+			echo "smtp_check: ".$data->smtp_check; 
+			echo "<br>\n";
+			echo "mx_found: ".$data->mx_found;*/
+			
+			//echo json_last_error(); 
+			//echo json_last_error_msg();
+
+
+
+		}
+
+
+		/*return [
+			'email' => $email,
+	        'format_valid' => $data->format_valid,
+	        'smtp_check' => $data->smtp_check,
+	        'mx_found' => $data->mx_found,
+	        'json_last_error_msg' => json_last_error_msg(),
+         	'json_last_error' => json_last_error(),
+        ];*/
+
+        return $data;
+
+
+	}
+}
diff --git a/update/2_4.sql b/update/2_4.sql
index f799fcb48..4f596e244 100644
--- a/update/2_4.sql
+++ b/update/2_4.sql
@@ -268,3 +268,6 @@ INSERT INTO `zz_emails` (`id`, `id_module`, `id_smtp`, `name`, `icon`, `subject`
 INSERT INTO `zz_email_print` (`id`, `id_email`, `id_print`) VALUES
 (NULL, (SELECT `id` FROM `zz_emails` WHERE `name` = 'Consuntivo' AND `id_module` = (SELECT `id` FROM `zz_modules` WHERE `name` = 'Contratti')), (SELECT `id` FROM `zz_prints` WHERE `name` = 'Consuntivo contratto')),
 (NULL, (SELECT `id` FROM `zz_emails` WHERE `name` = 'Consuntivo' AND `id_module` = (SELECT `id` FROM `zz_modules` WHERE `name` = 'Preventivi')), (SELECT `id` FROM `zz_prints` WHERE `name` = 'Consuntivo preventivo'));
+
+-- apilayer API key (per validazione email, piva, indirizzo ecc...)
+INSERT INTO `zz_settings` (`idimpostazione`, `nome`, `valore`, `tipo`, `editable`, `sezione`) VALUES (NULL, 'apilayer API key', '', 'string', '1', 'Generali');
\ No newline at end of file