mail software for multiple addrs

["Vladimir Z. Nuri" <vznuri@netcom.com>]

hi everyone. I'm asking this here because I know that cpunks
spend a lot of time in email. I'm looking for some GUI
software that can deal well with

1. multiple internet providers - i.e., if I have multiple
providers, I would like the software to be able to easily
deal with them all, without having to retype IP addresses
etc. into dialog boxes

2. multiple email accounts - i.e. the mail software is not
going to use merely one POP account, but should be able
to have different email addrs and passwords over POP

3. multiple mailing lists - I'd like a way to sort incoming
mail into separate folders/directories based on  header
fields, and a way to automate this. (i.e. not have to
go through the same procedure each time of typing the
fields etc.)

I am aware of Netscape's mail features, which don't really
handle much of the above.  also, I suspect many people
require some combination of the above, so there is probably
software out there to do it.. at least there is a demand.

also, I'm aware of procmail but would prefer something
that supports a GUI interface.

also, if you know of a better place to post this query, please
tell me.

thanks much;