Re: Storage: service provider vs user

On 12-feb-04, at 22:33, Hector Santos wrote:

>> For instance, the user may be connecting over a slow link and not want
>> to download everything just yet, or the user uses several computers to
>> read mail and wants to make sure each of those has a copy before the
>> message is removed from the server. A way to track how many clients 
>> are
>> supposed to get copies of a message and how many have already would be
>> useful here.

> In other words, it requires a redesign where the server requires 
> multiple
> "received" flags in the header.

Yes.

> One that says he received it at the system
> level and one that related to the human and presented as being 
> received.

Ok, that would be the next step. Do we need this, and do we have any 
reasonable way to achieve it? Remember that humans make for a lousy 
platform for implementing protocols.

> In our system, we called the "Preview Mail" problem because that is
> basically what a system will need to do if he doesn't add a multiple 
> receive bit concept to identify the different methods a message was 
> previewed.  One that allows a message to be redownload and one that 
> tells the system the user did receive the message.  The user can't lie 
> now

Just because the computer downloaded the message you don't know if the 
user read it. Just because the message was on the screen you don't know 
that the user was looking... I don't think it's _possible_ to make a 
system where the only two possible states are "the recipient hasn't 
read the message" and "the recipient has read the message and the 
sender knows this".