Hi,
In direct answer to your questions:
- The recipient collects from sender.
- Sender pays with a digital prepaid card.
Can the amount charged to the sender vary, based on whether or
not the recipient thinks the message is spam?
I.e., I wouldn't want to charge my family or friends anything (in
most cases ;-), but I would want to charge spammers.
That is application dependent. The perl code I made available is very
basic and does not differentiate but surgemail (www.netwinsite.com) has
integrated whitelists and spam ranking algorithms. So if a person is on
your white list, they are not charged. Different implementations can
decide when to engage the postage requiered feature depending on
different thresholds.
- the stamp is not attached since it could be reused by others,
instead a unique stamp (alphanumeric character) is issued and
is valid for one transaction.
- A filter detects the postage, autheticates it, and forwards it
for delivery if payment checks out.
Does this mean that all mail has to be processed through a
central system? If so, is that then forwarded on to the users normal
mailbox elsewhere in the world, or are they required to come to the
central system to pick up their mail?
How do you deal with mail which doesn't have a stamp?
No the mail is always routed to the proper SMTP server with postage
support, and each implementation does what is sees fit. The current
implementation saves the message in "hold" directory and send a payment
notification to the sender. The email is assigned a unique id, and the
payment url contains that id. Once payment is done, centipaid sends a
payment notification to the SMTP server, which release the email for
delivery. If no payment is done, the message is deleted.
In essence the user does not have to resend the message or have the
message held by any other entity.
If the message has a stamp header, the stamp number is queried with
centipaid and if a payment has been made, the message is delivered
without holding.
Note that the current solution is a step forward towards full support of
postage in emails, which will ultimatly occur. AMDP addresses these
issues, and I am sure we will discuss them on this list many times :)
Hope this helps.
Adonis
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