On Thu, 16 Feb 2006, Mark Shewmaker wrote:
On Thu, Feb 16, 2006 at 11:21:29PM -0500, Stuart D. Gathman wrote:
If you immediately reject invalid
RCPT TO, spammers use that to launch dictionary attacks. By delaying
until DATA, they get no information on valid emails.
Or you could delay a couple seconds for every invalid RCPT TO.
Or you could also use honeypot addresses (i.e. tom@ & jerry@ if those
users are not present) and if RCPT TO with such address comes in, then
record client ip and greylist it for a while.
--
William Leibzon
Elan Networks
william(_at_)elan(_dot_)net
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