diff --git a/class/actions_sendrecurringinvoicebymail.class.php b/class/actions_sendrecurringinvoicebymail.class.php
index fcae1d4..ceb5417 100644
--- a/class/actions_sendrecurringinvoicebymail.class.php
+++ b/class/actions_sendrecurringinvoicebymail.class.php
@@ -120,8 +120,8 @@ class Actionssendrecurringinvoicebymail
             'to'       => implode(', ', $mailObject->compileEmails('to', true)),
             'cc'       => implode(', ', $mailObject->compileEmails('cc', true)),
             'bcc'      => implode(', ', $mailObject->compileEmails('bcc', true)),
-            'errorsTo' => $conf->global->MAIN_MAIL_ERRORS_TO,
-            'replyTo'  => $conf->global->MAIN_MAIL_ERRORS_TO,
+            'errorsTo' => (isset($conf->global->MAIN_MAIL_ERRORS_TO) ? $conf->global->MAIN_MAIL_ERRORS_TO : ''),
+            'replyTo'  => (isset($conf->global->MAIN_MAIL_ERRORS_TO) ? $conf->global->MAIN_MAIL_ERRORS_TO : ''),
             'subject'  => $mailObject->subject,
             'message'  => $mailObject->body,
             'ishtml'   => $mailObject->body_ishtml,