Hi laura,
On 3 Aug 2004 at 8:01, laura wolk spoke, thus:
> It's good to see such a knowledgeable person on the list! Your posts are
> great and incredibly informative, not just about the bn but about computers
> in general. I am just asking for clarification about something you said.
> You wrote: "since the braillenote does not check with the server whether
> it has downloaded mail it already has, as other clients do, perhaps using
> the provided rfc 1939 uidl utility command or by calculating a hash of the
> mail against mail already in the local repository, it simply goes right
> ahead and redownloads agrivating your disk full condition, probably the
> reason why it stopped in the first place."
>
> It was my understanding that the bn did check with the server for
> duplicates it already had stored in the inbox, if not self-created folders.
> I had an experience semi-similar to that of yours and Paul's, but with
> only 85 messages or so. My bn hung up at 61, I exited, and when I
> reconnected to the pop server, it said I had 85 messages again. However,
> message 1 through 61 took less than one progress beep to skip over, and
> messages 62 through 85 took 4 or 5, (my db was pretty full at the time), as
> exp ected. When I asked, I was told by Roselle that the bn would not
> download duplicates of messages already stored in the inbox. For instance,
> after this particular session, I was told I had 24 new messages, not 85.
> So, are you saying that with both you and Paul, you attempted to reconnect
> and your bn began downloading a second copy of each message? Just looking
> for clarification. Thanks! Laura
>From what I can gather, based on the mentioned and other experiences and
notes about the KeyMail program that I have made myself, the salient facts
are as follows:
The KeyMail program does download all messages again on each reconnection
to the POP3 server (i.e. uses the RETR command - see RFC 1939) when mail
is available and listed by the server, as advertised by the LIST command.
This is coroborated by the POP3 service logs on the POP3 machine where all
the maildrops for myself and my family and friends are stored, which
logged the entire incident I mentioned. As such, the BrailleNote doesn't
check with the server, it does its copy calculation on the client. For
the minimum POP3 protocol allowed, this would be necessary. However, if
UIDL were available this would be server-side responsibility that the
BrailleNote could and should harness to achieve the desired effect.
Presently, only the Message-ID field of each message (see RFC 2822) is
checked as a way of determining if a message is already downloaded, and
only after the download of all of the mail is complete is this check
apparently done. This means that any disk full condition is agrivated
during the redownloading of the mail. In one of those brilliantly
piercing moments of software engineering irony, the BrailleNote's own
email program does not generate Message-ID fields itself on new mail - the
end result is that if you send a message with the BrailleNote and then
download it over and over again without deleting from either the server or
the BrailleNote, you will get multiple copies of it in your Inbox, even
though there is only one message on the server. This does not hold true,
for instance, by an email composed on an RFC2822-compliant email program
such as is found on your PC. the Message-ID field is a requirement of RFC
2822. It should be noted that RFC 2822 does stipulate that a client
should be ready for the situation where the Message-ID field is identical,
since these IDs are often not unique as intended. In such cases, message
hashes and other techniques can be used to further differentiate the mail.
There is little more to say, except that you must have a very fast net
connection!
If you have any more questions, feel free to ask away.
Cheers,
Sabahattin
--
Thought for the day:
Concerto (n): a fight between a piano and a pianist.
Sabahattin Gucukoglu
Phone: +44 20 7,502-1615
Mobile: +44 7986 053399
http://www.sabahattin-gucukoglu.com/
Email/MSN: <[EMAIL PROTECTED]>
