Re: POP3 "resume download" extension

Anders Rundegren wrote:
> 
> I've had some thoughts about an extension to POP3 that will let you
> resume a download of an interrupted transfer. These days people tend to
> send each other messages with large attachment, 2-3Mb is not that
> uncommon. Many clients connecting to their ISP, or even the ISP itself,
> have their modems improperly setup which causes a flaky phoneline,
> resulting in a premature disconnect.
> 
> At present, these messages will have to be re-downloaded from scratch
> taking a lot of unnecessary bandwidth from the ISP, not to mention
> resources within the system itself. Since a majority of the ISPs today
> are still using POP3, as opposed to IMAP (mostly due to the reduced
> diskspace required when serving a huge numbers of users), I think this
> might be a good idea.

An interesting thing about IMAP is that is fully supports the model of
message management that POP provides where messages are moved from the
server to the local machine and deleted from the server. However, very
few clients are built to support using IMAP in that fashion. They almost
all assume that if you're using IMAP, you only want to keep your
messages remotely. If an IMAP server were to disallow remote folders,
you'd have essentially the equivalent of a fancy POP server. And it
would have no higher diskspace requirements than any POP server would
require.

	Tony Hansen
	[email protected]