diff -u b/core/includes/mail.inc b/core/includes/mail.inc
--- b/core/includes/mail.inc
+++ b/core/includes/mail.inc
@@ -124,7 +124,6 @@
   if (empty($site_mail)) {
     $site_mail = ini_get('sendmail_from');
   }
-  $from = $site_mail;
 
   // Bundle up the variables into a structured array for altering.
   $message = array(
@@ -132,7 +131,7 @@
     'module'   => $module,
     'key'      => $key,
     'to'       => $to,
-    'from'     => $from,
+    'from'     => $site_mail,
     'reply-to' => $reply,
     'langcode' => $langcode,
     'params'   => $params,
@@ -148,12 +147,10 @@
     'Content-Transfer-Encoding' => '8Bit',
     'X-Mailer'                  => 'Drupal'
   );
-  if ($from) {
-    // To prevent e-mail from looking like spam, the addresses in the Sender and
-    // Return-Path headers should have a domain authorized to use the
-    // originating SMTP server.
-    $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $headers['Errors-To'] = $from;
-  }
+  // To prevent e-mail from looking like spam, the addresses in the Sender and
+  // Return-Path headers should have a domain authorized to use the
+  // originating SMTP server.
+  $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $headers['Errors-To'] = $site_mail;
   if ($reply) {
     $headers['Reply-to'] = $reply;
   }
@@ -188,7 +185,7 @@
       $message['result'] = $system->mail($message);
       // Log errors.
       if (!$message['result']) {
-        watchdog('mail', 'Error sending e-mail (from %from to %to).', array('%from' => $message['from'], '%to' => $message['to']), WATCHDOG_ERROR);
+        watchdog('mail', 'Error sending e-mail (from %from to %to with reply-to %reply).', array('%from' => $message['from'], '%to' => $message['to'], '%reply' => $message['reply-to'] ? $message['reply-to'] : t('not set')), WATCHDOG_ERROR);
         drupal_set_message(t('Unable to send e-mail. Contact the site administrator if the problem persists.'), 'error');
       }
     }