* code for task#1639.

module/mail/control.php

@@ -158,4 +158,16 @@ class mail extends control
         $this->view->users      = $this->dao->select('account,  CONCAT(realname, " ", email) AS email' )->from(TABLE_USER)->where('email')->ne('')->orderBy('account')->fetchPairs();
         $this->display();
     }
+
+    /**
+     * Reset the email config.
+     * 
+     * @access public
+     * @return void
+     */
+    public function reset()
+    {
+        $this->dao->delete('*')->from(TABLE_CONFIG)->where('module')->eq('mail')->exec(); 
+        $this->locate(inlink('detect'));
+    }
 }

module/mail/lang/en.php

@@ -5,6 +5,7 @@ $lang->mail->detect = 'Detect';
 $lang->mail->edit   = 'Configure';
 $lang->mail->save   = 'Successfully saved';
 $lang->mail->test   = 'Testing';
+$lang->mail->reset  = 'Reset';
 
 $lang->mail->turnon      = 'Turnon';
 $lang->mail->fromAddress = 'From email';

module/mail/lang/zh-cn.php

@@ -5,6 +5,7 @@ $lang->mail->detect = '检测';
 $lang->mail->edit   = '编辑配置';
 $lang->mail->save   = '成功保存';
 $lang->mail->test   = '测试发信';
+$lang->mail->reset  = '重置';
 
 $lang->mail->turnon      = '是否打开';
 $lang->mail->fromAddress = '发信邮箱';

module/mail/view/edit.html.php

@@ -64,6 +64,7 @@ include '../../common/view/header.html.php';
        <?php 
        echo html::submitButton();
        if($this->config->mail->turnon and $mailExist) echo html::linkButton($lang->mail->test, inlink('test'));
+       echo html::linkButton($lang->mail->reset, inlink('reset'));
        ?>
      </td>
    </tr>