[BirdOPrey5]

Install this mod: https://vborg.vbsupport.ru/showthread.php?p=2141404

The go to your Admin CP -> Products & Plugins -> Plugin Manager

Edit the plugin called: Register Group

Delete all the PHP code and replace it with the following (copy and paste it in):

global $vbulletin;
		if ($vbulletin->options['reg_group_enable'])
		{
		   if ($vbulletin->options['reg_group'])
		   {
                   if (preg_match("/mil$/" , $vbulletin->userinfo['email']))
                     {
		       $newuser = $vbulletin->db->query_first("SELECT * FROM " . TABLE_PREFIX . "user
        ORDER BY userid DESC");
        $vbulletin->db->query_write("UPDATE " . TABLE_PREFIX . "user
        SET usergroupid = '" . $vbulletin->options['reg_group'] . "'
        WHERE userid = '".$newuser['userid']."' ");
		     }
                   }
		}

Now go setup the mod per instructions... it will move only people's who's email addresses end in "mil" to the usergroup you specify in options. Everyone else will go into the default "registered users" group.