mail server/webmail

[Liontaur]

Hi folks, I was searching around but i'm not quite sure what i'm looking
for. I want to have a program that gets the mail from my ISP mail server
(pop), stores the mail permanently, allows me webmail access, and also lets
me grab the mail with a mail client (Outlook Express). I'd like to be able
to sync the mail with outlook express also. Like if I send a mail over
webmail, that sent mail will also go into the sent box in outlook express,
or conversly, perhaps store all the mail on the server and have outlook
express just show the folders and contents stored on the server. But i'd
have to somehow upload all of the mail currently in my outlook express. I'll
also need some kind of spam functionality as I get a sizable amount of spam.
Currently I use K9 for spam and I quite like it.

Thanks for any help you can offer folks!

Mark