Passive Spam Revocation (PSR)
Currently almost all mail systems (e.g. Hotmail and Gmail) use a spam
filter, which can drop good and important messages.
I propose an optional feature for current mail systems. The main idea
is if a message is considered spam, this spam status can be tracked by
the sender (but not sent to him directly, as the From field can be
faked). The message can be re-marked as "not spam" if the sender can
solve a CAPTCHA.
STEP 1: A is going to send B a message. A's mail client generates a
random code and puts it in a custom field in the outgoing message's
header:
Code: <random code>
STEP 2: A's mail client sends the message, waits 30 seconds, and then visits:
https://spamstatus.<B's mail domain>/?msgid=<Message-ID>&code=<Code>
This page displays one of these possible "spam statuses":
* MESSAGE CONSIDERED SPAM. (A CAPTCHA is also presented below.)
* MESSAGE CONSIDERED NOT SPAM.
* PENDING. PLEASE TRY AGAIN LATER.
* All other responses mean B's mail system doesn't support this feature.
In the first case, A's mail client will report the status and the
CAPTCHA to A. A can choose to solve the CAPTCHA to prove the message
is not spam.
Like the idea? Here is the official Google group for it:
http://groups.google.com/group/passive-spam-revocation
Regards,
Yao Ziyuan
http://sites.google.com/site/yaoziyuan/