[Mimedefang] New spam technique
WBrown at e1b.org
WBrown at e1b.org
Tue Jul 6 10:02:04 EDT 2004
mimedefang-bounces at lists.roaringpenguin.com wrote on 07/05/2004 02:27:49
PM:
> That doesn't work if there is more than one recipient, some valid and
some
> invalid. At the end of DATA, you can only indicate success or failure
for
> the entire message and all recipients.
>
> Exchange does this by default; it's forced to generate NDN's for invalid
> recipients.
>
> Really, there needs to be an extension to SMTP that lets you return
> multiple success/failure codes after DATA (one code per recipient).
But if you return a code at the end that says baduser at domain.com is
invalid, but gooduser at domain.com is valid, have you really changed
anything from when you failed it after RCPT TO? It doesn't seem that way.
The spammers still know which addresses got through, and which ones were
rejected and they can still clean their lists.
More information about the MIMEDefang
mailing list