On Sat, Oct 23, 2004 at 07:18:57PM +0800, test wrote:
The advantages of the new technique: 1.As a receiver,you first
judges the useful of the email by simple
information(email-pointer:subject,from,to and etc).if is,you can
refuse it to forbid download the body of the email(reducing the
Internet flux)
This is not an advantage over existing SMTP.
Case 1: If you can judge by the given simple information
(basically the mail header), then you could simply discard/tag
the message after reception or even abort the connection after
transmission of the header. (Violation of SMTP, but spam is an
excuse). So there is not advantage over SMTP.
Also no advantage from user's point of view. If you can
tell from sender/subject that it is spam, than you won't read
it. Just a bandwidth matter.
Case 2: If you can't judge, then you need to fetch the message
anyway. Again, no advantage.
This is also a legal problem:
What is the transmission time? Imagine you have to fulfill a
contract by sending something by email. When did you fulfill?
when the receiver starts to fetch? How long would you have to
keep your server online? A day? A week? A month?
The proposal is not new, and has been discussed on ASRG about
more than a year ago.
You furthermore run into several problems:
When will the server be allowed to delete the message? After a
download? What if the message is aliased to several recipients?
How would the sender tell how many downloads it will take for
all recipients to get the message? What if the recipient never
downloads?
What if the diskspace of the server is exhausted?
It is also a security problem: You need to protect the server against
faked fetches. E.g. if a message is forwarded or bounce to someone
else, the new recipient could delete the message from the server.
BTW, it is not correct to assume that all people use pop3 to
fetch messages. How should someone fetch emails when not online?
(e.g. I do use UUCP).
And, ironically, it makes spammer's life even easier:
Your proposal makes sending email much more complicated for those
who deliver normal mail.
But for those who do mass mailing and are sending the same message
a million times, your proposal saves a huge amount of bandwidth,
because they need to transmit the header only and to keep just a single
message available for download for those who read the message.
So it just reduces the bandwidth needed for spamming. That's not exactly
what an anti-spam-system can be expected to do.
regards
Hadmut
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