Sync IMAP messages from multiple computers

I use three different computers to check my email with outlook 2003.
The Sent folder is different from one computer to another, and shows just the messages I send from that particular computer.

Is there a way to sync the Sent folder?
Can I have the Send folder from my work computer show the same on my home computer and vice-versa, as well as on the web mail?

I assume it is a simple setting, I just can’t find it.

My try for a website:
ArhisStudios: Architecture Visualization Graphics