well...i don't think redirector will work - since the person w/ the laptops email will have to be going to the "always on" computer - and it will only work w/ one account
you can try using the mail connector - if you have a BIS 2.x account it can be shared. You would install the frist version on the computer that's always on and enable sharing
then, install it on the laptops and enter in the Mail Connector ID (you'll get that after enabling sharing). one mail connector can be shared by up to 5 ppl
then, as long as the "always on" comptuer is well - always on, the person w/ the laptop will still get their emails.
hope this helps...you can take a look at this link as well for further help Livelink - Redirection