Setting KMail's To Do flag

[Steven Ihde <steve@x2.hamachi.us>]

Hi,

I hope someone can suggest a solution to my problem.  I want to maintain a 
cached copy of email on my laptop disk so I can:

1. Set KMail's "To Do" flag (or something similar) while at work, and then
2. deal with mails marked "To Do" while I'm on the train with no net 
connectivity.

Using KMail's disconnected IMAP seems like it should work.  There's just one 
problem -- checking for new mail is so slow it's unusable.  It takes  more 
than five minutes to do one check for mail -- every time.  It spends most of 
the time in the "uploading status of messages" phase.  I have about 
16000 messages in the folder -- should I expect dimap to perform well in this 
situation?  Using KMail's regular imap, a check for new mail on the same 
folder is virtually instantaneous.

I also tried using the script "offlineimap" to maintain a cache on the laptop 
disk.  But the problem here is that KMail doesn't propagate the "To Do" flag 
(or any other flags except the basic read/unread status AFAICT) to the 
server, so the cached copy doesn't get the flag status.  :-(  Is there a way 
to force KMail to store the flags on the server instead of in its cached copy 
of the headers?

BTW, the IMAP server is Courier running on a sarge box, and is under my 
control if it makes any difference.

Thanks,

Steve