Re: [Off Topic] Need review for POP3 extension mechanism

Randall Gellens wrote:

> At 8:46 PM -0700 7/22/98, Mike Gahrns wrote:
>
> >Having said that, perhaps a better solution would be to define another
> >arguement called "USER".
> >If a client does a CAPA and gets an EXPIRE USER, in the unauthenticated
> >state, it knows that the server supports per user expiry settings.  It
> >explicitly informs the user when they need to re-issue the CAPA command
> >after authentication due to per user options.
>
> I'm not sure the added complexity would buy us anything useful.  The
> EXPIRE setting can only be a rough guide to the user, never accurate
> (without some complex per-message expiration warning mechanism).  Even
> if the server presents the currently accurate value for a specific
> user, that value could change, the user doesn't know how long the
> message has already been on the server, and some servers could change
> the expiration period after the user has seen the message.  So I think
> the most that can be usefully done with a simple mechanism is to handle
> the no-LMOS and indefinite-LMOS states, and for everything else, inform
> the user, especially if the user tries to set the client's LMOS setting
> to a value within some threshold of what the server's reported EXPIRE
> value.

Imagine, for example, that server calculates the minimal EXPIRE value for all
users and returns it in the unauthenticated state. Let user A have EXPIRE value
equal to 0 and user B has EXPIRE >0 (5 for example). Described server will return
EXPIRE 0 in unauthenticated state, but it will not be the truth for user B.
I think that something like EXPIRE USER will help to solve such problem.


One question about EXPIRE 0 : Am I right that all messages will be deleted after
QUIT command. What happens if client disconnects without QUIT? How client can
prevent messages from being deleted?

Cheers,
Alexey Melnikov
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SMTP/POP3/IMAP4/ACAP servers creation team
"ACAP Explorer" client
Imap Development Kit (my own product)

Epsylon Technologies, Russia
 http://www.demo.ru
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