The main reason for the proliferation of spam is that the cost of sending a
message is so small for the sender. The real cost - for delivery, anti-spam
tools, personal reading and rejection of spam, is a cost for the recipient, not
for the sender. I myself spend about 15 minutes a day on opening and rejecting
spam messages, even though I use multiple spam filter. The total cost for all
internet mail users is billions of dollars.
I think that the only workable method of getting rid of spam is to charge the
sender of messages a price of perhaps 0.10 $/recipient for sending messages.
To implement this, we should set up a network of smtp stations (MTAs) which
charge a price of perhaps 0.10 $ for receiving a message and transmitting it to
its recipient. We might perhaps call such stations CMTA (for Charged Message
Transfer Agents) This network should be separate from the existing network of
mail transfer agent. a CMTA should not charge for messages coming from other
CMTAs) A secure method must be defined so that a recipient can distinguish
between messages from the CMTA from messages from other non-charged MTAs.
Probably some kind of cryptographic method has to be defined. A way of reducing
the right to act as a CMTA must be found for CMTAs who represent spammers.
I believe that people will be willing to accept the complication of receiving
messages from two SMTP networks, the conventional network and the new CMTA
network. Mailing lists must be handled within the CMTA network, so that the
sender of a message to a mailing list need only pay 0.10 $ for sending the
message to all members of the mailing lists. I am not yet sure how to avoid
spammers from misusing large mailing lists, but probably a human has to approve
every message before it is distributed to members of mailing lists.
The income, 0.10 dollars per recipient, can be used to set up and manage the
network of CMTAs, paying for the human monitors of messages to mailing lists.
Any surplus might go to IETF. We should avoid systems run by private companies
for their own profit.
Invoices sent by conventional e-mail should be invalid, and the recipient need
not pay such invoices.
My proposal will not stop such spam where the sender is willing to pay 0.10
$/recipient to submit the message. But propably this will be a very small
percentage, perhaps 1 % och 0.1 %, of the present amount of spam.
Recipients should set up their mailers so that messages coming from CMTAs get
higher priority and messages coming from the old mail network will get lower
priority, or perhaps dismissed without being read. Possibly put charged
messages into a different mailbox than no-charged messages.
There are several technical details to be resolved to realize the network of
CMTAs, but IETF should be able to resolve these details and define a variant of
SMTP for transmissions to and between CMTAs. And I do not think any other
anti-spam method will work. Details to resolve:
- How to handle the payments for sending mail to CMTAs and distributing the
- How to block malicious fake CMTAs.
- How to send and receive charged messages.
- How much to charge for sending a message, price per recipient.
- How to set up the network of CMTAs.
- How to handle mailing lists, where the price for the sender cannot be 0.10 $
per member of the mailing list.
Professor emeritus Jacob Palme <jpalme(_at_)dsv(_dot_)su(_dot_)se> (Stockholm
for more info see URL: http://www.dsv.su.se/jpalme/
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