Just like with phone calls, an useful principle here should be that the most
important email is usually not what a user sends but what he receives. For
example, receiving a request for a quote. Another useful principle is that
replies, such as a reply to a quote sent to a client, usually rank even higher
However, today, it's difficult to connect what a user is willing and
desiring to receive (SMTP) with what he is willing to read (POP)
and has actually read (mail agent). These act as independent hands, one
hand not knowing what the other is doing. In a practical sense, this reduces
user-defined, trusted, and realtime control information that could be
made, otherwise, automatically available to the SMTP and POP agents.
This also makes it harder to user-prioritize (and, possibly, reject) mail
when it is received by SMTP .
Imagine, for example, if the NG POP agent could inform the NG SMTP
agent that an email with the same subject and content has already being
received and was tagged by the user as spam. This would be, of course,
much more valuable than spam-tagging by some filter. To enable this,
however, NG POP should also have an expanded capability of tagging
messages, in addition to delete and read.
I note that this capability exists today already to some extent, when ISPs
use successful POP authentication as a way to allow SMTP services to be
provided to a user sending mail, timing out after a certain period.
What we see here can be called a requirement for coherence . There
should be coherence between the messages a user is willing to read and
the messages he is willing to receive, for example. This is, of course, not
limited to SMTP and POP. To summarize:
- Users would like to be able to define the degree of coherence between
messages that can be received (for any purpose) and messages that have
- Users would like to be able to define the processing of messages BEFORE
they are received, based on their degree of coherence. This includes rejection
and qualified acceptance.
- Users would like to be able to define the processing of messages AFTER
they are received, based on their degree of coherence. This includes
for user attention and sending automatic responses.
Messages with low coherence could, at any stage, be designated for a challenge
process, individual verification, rejected outright, or processed according to
some rule chosen by the user. Messages with high coherence, for example,
could be forwarded to a SMS phone, or tagged for immediate attention.
It seems also that coherence requirements might summarize well some other
lower-level requirements, providing a high-level requirement that is more
general than any such particular cases.
 Allowing mail to be effectively processed/rejected right at the SMTP agent
is more economical, faster and less confusing for both sender and receiver
than processing/rejecting mail at the POP agent -- if it can be reliably done.
 Definition: coherence is a logical or natural connection. It can
be provided by non-algorithmically by a user (natural) or as the
result of a rule or calculus. Coherence is a matter of degree, from
0% (no connection) to 100%. Coherence includes header and body