diff --git a/b2mail.php b/b2mail.php
index f1a90a9339..9b8e49cc17 100644
--- a/b2mail.php
+++ b/b2mail.php
@@ -211,7 +211,7 @@ for ($iCount=1; $iCount<=$Count; $iCount++) {
 				$content = addslashes(trim($content));
 				$sql = "INSERT INTO $tableposts (post_author, post_date, post_content, post_title, post_category) VALUES ($post_author, '$post_date', '$content', '$post_title', $post_category)";
 				$result = $wpdb->query($sql);
-				$post_ID = mysql_insert_id();
+				$post_ID = $wpdb->insert_id;
 
 				if (isset($sleep_after_edit) && $sleep_after_edit > 0) {
 					sleep($sleep_after_edit);