On Fri, Feb 21, 2003 at 09:46:35AM -0500, Ken Murchison wrote:
- usenet puts a greater restriction on the headers (although still being
RFC 2822 compliant)
And of course has its own extra headers.
- mail messages are typically tranmitted over a 1-to-1 protocol (SMTP)
and news articles are typically transmitted over a 1-to-many protocol
(NNTP)
That is the key difference. In E-mail, you have control over whom
you are sending messages to, even if you have a giant mailing list.
You have the ability to know who they are and possibly ask them
questions about what they want. Many mailing lists (see yahoo groups)
let list members put in a setting saying if they want HTML or plain
text mail from the list for example.
USENET is a broadcast format. You don't know who's reading, they have
no ability to set a preference, so you must transmit in a form that
all of them can handle, and all of them must be ready to handle
any form that is transmitted.
This makes migration of forms much harder, believe it or not, than
in mail. Taken strictly, nobody can use a new form in news until
everybody is ready to receive it, which is impossible, so the net
does sometimes break into subnets to try out new things when it must.
Note that NNTP is not a one to many protocol itself. It is USENET
itself that is the one to many, simulating broadcasting through the
use of a collection of 1 to 1 protocols. Though in theory (and
briefly once in practice) USENET could be done via IP multicasting.