diff --git a/htdocs/admin/mails.php b/htdocs/admin/mails.php
index 1c59d1bb26d..515357df904 100644
--- a/htdocs/admin/mails.php
+++ b/htdocs/admin/mails.php
@@ -562,9 +562,9 @@ if ($action == 'edit') {
 
 	if (empty($conf->global->MAIN_DISABLE_ALL_MAILS)) {
 		// Force e-mail recipient
-		print '<tr class="oddeven"><td>'.$langs->trans("MAIN_MAIL_FORCE_SENDTO").'</td><td>'.$conf->global->MAIN_MAIL_FORCE_SENDTO;
-		if (!empty($conf->global->MAIN_MAIL_FORCE_SENDTO)) {
-			if (!isValidEmail($conf->global->MAIN_MAIL_FORCE_SENDTO)) {
+		print '<tr class="oddeven"><td>'.$langs->trans("MAIN_MAIL_FORCE_SENDTO").'</td><td>'.getDolGlobalString('MAIN_MAIL_FORCE_SENDTO');
+		if (!empty(getDolGlobalString('MAIN_MAIL_FORCE_SENDTO'))) {
+			if (!isValidEmail(getDolGlobalString('MAIN_MAIL_FORCE_SENDTO'))) {
 				print img_warning($langs->trans("ErrorBadEMail"));
 			} else {
 				print img_warning($langs->trans("RecipientEmailsWillBeReplacedWithThisValue"));
diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index e3a218711dd..5151a0a39dc 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -41,6 +41,29 @@
 
 include_once DOL_DOCUMENT_ROOT.'/core/lib/json.lib.php';
 
+/**
+ * Return dolibarr global constant string value
+ * @param string $key key to return value, return '' if not set
+ * @return string
+ */
+function getDolGlobalString($key)
+{
+	global $conf;
+	// return $conf->global->$key ?? '';
+	return (string) (empty($conf->global->$key) ? '' : $conf->global->$key);
+}
+
+/**
+ * Return dolibarr global constant int value
+ * @param string $key key to return value, return 0 if not set
+ * @return int
+ */
+function getDolGlobalInt($key)
+{
+	global $conf;
+	// return $conf->global->$key ?? 0;
+	return (int) (empty($conf->global->$key) ? 0 : $conf->global->$key);
+}
 
 /**
  * Return a DoliDB instance (database handler).