At 08:18 PM 2003/12/22 -0500, you wrote:
The LMAP discussion document (based on Hadmut's comments in RMX),
says that the single hop use of SMTP is a large part of the reason why
spam is so wide-spread. There are 100's of millions of senders, each
sending to only 100's of thousands of recipient MTA's.
> How is this behavior helpful to stopping spam?
If that imbalance in the network was addressed, spam would become
significantly more manageable. It wouldn't stop entirely, but having
a blacklist of 100K MTA's is signficantly easier than having
blacklists of millions of IP's.
I have no particular expertise in mail servers or the Internet RFCs. My
viewpoint is thus quite simplistic.
I agree completely that the RFCs have to be changed, or some other
mechanism, so that MTAs only take in email from other MTAs or authenticated
clients of the MTA. Recipient MTAs only accept emails from MTAs in the
name lookup portion of the DNS. Then we need some mechanism of ensuring
that the recipient MTA is really receiving the email from the originating
MTA.
From my very simplistic view of the email systems it seems to me that the
msgid id could be part of the verification mechanism. The originating MTA
stamps the outgoing email with a unique message id. Once the header
portion of the email is received then the recipient MTA does a name lookup
on the originating MTA and verifies that the originating MTA sent that
msgid. Once the receipient MTA finishes accepting the email the
originating MTA then never uses that msgid again.
And if all of this means updating the worlds email servers over the next
year or two, well tough. I for one am getting real tired of getting a
hundred bounces a day from spammers forging email address for my domains
and 200 or 300 Swen virusses a day. And my domains and I are an
insignificant portion or the worlds email traffic.
Tony
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Tony Toews, Microsoft Access MVP
Microsoft Access Links, Hints, Tips & Accounting Systems at
http://www.granite.ab.ca/accsmstr.htm