I need help setting up IMAP

I check my email on several devices (personal and work laptops, iPad and iPhone, plus web mail). I am trying to set up my IMAP account so that when I check mail on 4 of those 4 things, the mail stays on the server, but when I check (or send) mail on the 5th device, the mail (both incoming and sent) is removed from the server. We only have a limited amount of server space and a high volume of emails, so permanently leaving it on the server isn't a good solution.

I had thought I had it set up correctly, but now my Sent mail isn't being saved anywhere (not on the server, nore on my laptop) and all my incoming mail seems to stay on the server, while also being downloaded as a copy onto my laptop.

My ideal situation would be 2 have 2 setups (for different devices):

Setup #1

Incoming mail: received, but stored on the server

Sent Mail: Sent and not saved anywhere.

Setup #2

Incoming Mail: Received and downloaded and removed from the server, stored only locally.

Sent Mail: Sent and saved only locally (if I have to save it on the server, I will delete periodically, but would rather not have to!)

I'm using OSX 10.7.5, BTW.

Any ideas?

Thanks!