[TriLUG] postfix spam blocking

[matt at noway2.thruhere.net]

> I'd like to explore the notion that "it was never meant to be
> [adjective]".  I too agree that people depend too heavily on email, but
> for different reasons that you've cited.  It seems to me that the
> use-cases for email came about precisely because it became effectively
> an instantaneous and reliable form of communication; I'm not currently
> aware of a better alternative for individual asynchronous communication.
>
>  From a pragmatic perspective, if we're comparing email to a postal
> letter, I would argue it *is* instantaneous.  5 minutes (usually less)
> sure beats 2 days of postal mail, and without the incurred cost of
> various peripherals.
>
>  From your listed examples, however, I'd argue that it's faster than a
> fax, and with better quality.  I will grant that it's not instantaneous
> in the synchronous sense of a phone call or instant message, but it has
> the advantage of not demanding attention right this second, whereas
> those two, to a large degree, do.  In regards to specifically the phone,
> it also has the advantage of being cheaper.  40 bucks (+/-) for an
> internet connection per month, compared with my friends' cell phone
> bills that I occasionally observer to be 80 or more ...
>
> Email is inherently a text medium, and, for the foreseeable future, will
> be; it won't -- can't -- replace aural forms of communication.  But for
> most business communication, and frankly, most asynchronous
> communication (in my life, anyway), email fits the bill.  Heck, if email
> weren't dependable (defined to be reliable and fast), there are certain
> businesses that would not exist.  Gmail anyone?  Google Apps?
>
> Cheers,
>
> Kevin

To this I would add:

Indication of message delivery, both at the server and application level. 
With access to server logs, it is possible to get a pretty good indication
of message delivery, at least to the point of where you have confirmation
that the next recipient MTA has accepted responsibility for the message. 
At the application layer, "read receipts" are easily requested.

Email can also provided integrity verification and confidentiality.  This
can be built into the server application, such as with domain keys and at
the application layer with PKE.

With the inclusion of these features and techniques, email provides very
fast, highly reliable communications that can be secure, authenticated,
and confirmed.  More or less a digital equivalent of certified mail.

In terms of security, the header chain provides a good audit trail of
origin as well as intermediate destinations.  While the header chain can
be spoofed, as when something is added to the bottom to cause backlash
spam, proper use of dkim can easily identify this as well as other
tampering.

Given the above, I find it ironic that in legal circles the preference
still seems to be on FAX and that digitally signed and authenticated
documents are not considered binding.