geeky question on read/unread mail

[Bob Chiodini]

On Mon, 2005-01-03 at 05:10, Tony Dietrich wrote:
> On Monday 03 Jan 2005 04:08, Globe Trotter wrote:
> > Hi,
> >
> > How do all these mailers tell whether an e-mail has actually been read or
> > not? By that, I mean, how does pine (or sylpheed or whatever) find out if
> > an e-mail has actually been read? Please note that I am not asking how they
> > indicate whether an e-mail has been read or not (this is different for
> > different mailers) but how to they find out whether each e-mail in the
> > folder should be classified as unread or read.
> >
> > This may well depend on format (MH or mbox or the like) but I still wonder
> > how this is settled.
> >
> > Thanks and best wishes!
> >
> If I understand correctly what you are asking, then the answer is that each 
> email reader keeps an internal record of whether you have viewed the emails.
> 
> You can verify this by running two separate mail readers pointing at the same 
> mail directory ... each reader will show the emails as read/unread depending 
> on whether you have seen the email in that particular reader.
> -- 
> Tony Dietrich

I would like to interject another question:  

What about when using an IMAP server (Cyrus)?  When I read mail on my
FC3 box using evolution the mail subjects change from bold to normal
indicating that the mail has been read.  If I go to a Windows box on the
same LAN and open Thunderbird, the emails read earlier by evolution are
usually (but not always, at least not immediately) marked as read in
Thunderbird.  However; opening unread emails in Thunderbird (on Windows)
does not mark the emails as read in evolution.  Is this a bug (evolution
or thunderbird)?  Doesn't IMAP provide the read/unread status through
the seen_db?

Pressing the Get or Send/Receive button does not update the read/unread
status on either evolution or thunderbird.

Bob...