diff --git a/adm/mail_select_form.php b/adm/mail_select_form.php
index 8aebfd80e..a8115297d 100644
--- a/adm/mail_select_form.php
+++ b/adm/mail_select_form.php
@@ -62,7 +62,7 @@ include_once('./admin.head.php');
     <tr>
         <th scope="row"><label for="mb_email">E-mail</label></th>
         <td>
-            <?php echo help("메일 주소에 단어 포함 (예 : @sir.co.kr)") ?>
+            <?php echo help("메일 주소에 단어 포함 (예 : @".preg_replace('#^(www[^\.]*\.){1}#', '', $_SERVER['HTTP_HOST']).")") ?>
             <input type="text" name="mb_email" value="<?php echo $mb_email ?>" id="mb_email" class="frm_input" size="50">
         </td>
     </tr>