On Jan 22, 11:56pm, Walter Dnes wrote:
}
} - Otherwise, if the email is not dropped or rejected (virus, etc), the
} receiving MTA sends a 599 return *WITH A SHORT MESSAGE/URL POINTING
} TO A CAPTCHA TEST*. (It doesn't have to necessarily be 599; this is
} just an example).
This technique is already "in the wild". It'd take me some considerable
digging to find the site, as it was a few weeks ago (it might be UC
Davis, but I really don't remember for sure), but I have encountered
an SMTP rejection where the 5.7.1 response text pointed to a web page
instucting one to paste the returned email message in a text area and
type the text from an image into another input field.
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg