Subject: Re: Recall email protocol

From: Keith Moore <[email-masked]>
Date: Fri, 4 Mar 2005 01:17:52 -0500

> Now, instead of sending e-mail messages all over the place, we only 
> send
> links.

it's already been defined.  read the MIME spec and look at 
message/external-body

then imagine what it would be like if everyone sent mail that way.

right now, mail is pretty robust across server and link failures.  the 
mail might be delayed, but it will get there when the server and/or 
link comes back up.   it's possible to arrange multiple paths by which 
mail can get to its destination.

if all mail were links, the mail would not get downloaded until the 
recipient actually read his mail.  this would suck if the originator's 
server or recipient's client were on a slow link, if the server were 
down, if the net were congested.  even on fast links, it would add an 
annoying delay every time a message was opened.  it would make very 
large attachments infeasible even if there were good connectivity 
between the recipient and his message store. the result would be that 
mail would be slower and less reliable than it is now, because it would 
depend not only on the forward path working (as it does now) but also 
on the path back to the originator's server working.

pre-fetching would be possible, but this would have another side effect 
- the sender would think the recipient had read his mail, even if the 
recipient hadn't decided to read that message yet.

it wouldn't help spam filtering much because most spam filtering 
actually needs to see the content of the message, and you can't do that 
without downloading it.  it would decrease the load on MTAs due to 
handling spam and shift that load to the sender's server (which seems 
appropriate) but wouldn't reduce the amount of spam in a recipient's 
inbox by a significant amount.

reading mail would be a lot like it is now, except that you'd have to 
wait longer for each message, and spam wouldn't be pre-filtered.

as for holding spammers accountable - spammers are already routinely 
sending mail via compromised systems and other people's accounts.  how 
would this cause them to stop doing so?

---

From: John C Klensin <[email-masked]>
Date: Fri, 04 Mar 2005 10:31:30 -0500

--On Friday, 04 March, 2005 01:17 -0500 Keith Moore
<[email-masked]> wrote:

>> Now, instead of sending e-mail messages all over the place,
>> we only  send
>> links.
> 
> right now, mail is pretty robust across server and link
> failures.  the mail might be delayed, but it will get there
> when the server and/or link comes back up.   it's possible to
> arrange multiple paths by which mail can get to its
> destination.
>...

Of course, none of the above has prevented a few companies from
deciding that the "send a link" model has commercial
possibilities for distribution/repository server operators.
"You send me the real content and a few dollars a megabyte and
I'll be sure the content is easily obtained when someone shows
up with a link or password" may actually be a good business
model for some circumstances.  It does add a few security twists
to the system, but, well...

   john