Re: Discovering users by RCPT TO

[Vince Hoang <vince () litrium com>]

On Thu, Jan 13, 2005 at 02:20:12PM -0500, Chris Buechler wrote:
> I'd recommend disabling it unless you get flooded by such spam
> attacks. I would probably consider it unnecessary information
> disclosure, depending on the environment and reason (if any)
> for doing it that way.

Some MTAs allow permit you to drop the session after a certain
number of failures, but that only slows down the dictionary
attacks.

You cannot disable RCPT TO because that is how the SMTP protocol
designates the recipients.

-Vince