perhaps instead of asterisks, the banner should be replaced with
220-This SMTP session is being munged by a cisco firewall that is
220-installed at x.y.z. If something breaks, the problem is likely
220-to be in the firewall, rather than your mail client or the server.
220-If you don't like this, contact our marketing department
220-and they'll explain to you that things are really supposed to be
220-this way. Of course they're all lying bastards, but it's easier
220 to believe them than it is to stop selling buggy products.