Index: sites/all/modules/smtp/smtp.mail.inc
===================================================================
--- sites/all/modules/smtp/smtp.mail.inc	(revision 2)
+++ sites/all/modules/smtp/smtp.mail.inc	(revision )
@@ -91,7 +91,7 @@
       // If from e-mail address is blank, use smtp_from config option.
       if (($from = variable_get('smtp_from', '')) == '') {
         // If smtp_from config option is blank, use site_email.
-        if (($from = variable_get('site_email', '')) == '') {
+        if (($from = variable_get('site_mail', '')) == '') {
           drupal_set_message(t('There is no submitted from address.'), 'error');
           watchdog('smtp', 'There is no submitted from address.', array(), WATCHDOG_ERROR);
           return FALSE;