squirrelmail works just fine - though I only use it when I have browser-only access to the internet. I would recommend using imapproxy with it to reduce the resources it uses.
Does anyone here use squirrelmail? Is it worthwhile? I like accessing email through outlook, but am looking for an alternative when I'm on the road (ie., using someone else's computer). What do you think?
Squirrelmail works fine, loads of people use it.
I prefer IlohaMail though. IlohaMail has more readable code if you care about that sort of thing. They both do the same job.
Outlook is a nasty mail client. It has a bad security history. You need dodgy rules just to make it store sent mail on an imap server. Plus if you ever want to use it with the same domain account on another computer and you are not using exchange you are stuffed. consider something else like maybe thunderbird.