diff --git a/smtp.php b/smtp.php
index fede61e..45e6e97 100644
--- a/smtp.php
+++ b/smtp.php
@@ -22,7 +22,8 @@ class smtp
   /** The SMTP server name or IP
     */
   public $server = "127.0.0.1";
-  /** The SMTP port
+  /** The SMTP port to use (if false, use 25 if no SSL or 465 if SSL,
+    * if user defined, use the user value)
     */
   public $port = false;
   /** The SMTPS support by tunnelling the session in SSL transport