I'm new to LP's email and was wondering if it was possible to set up a web based email client which supports multiple email addresses.

Basically I am looking to be able to log in with a single set of credentials, and be able to access multiple email addresses. Ideally, each email address would just show up as its own folder with the ability to switch between them quickly without having to login/logout of them individually.
 

I don't know if you've found a solution, but I use crackerMail.  Its not secure itself, so I put it in its own folder that I secured with cPanel (htaccess).  I log in, and have access to my various e-mails here, and a few elsewhere.

2.5 bummers:
1) Doesn't keep sent.
2) You may need to get in and tweak the code deleting subject lines. It took me a bit to figure out why I could not delete some e-mails - turned out to be special characters in the subject.
.5) Everyone once in awhile, it gets agitated.  Not "sweet Jesus, I lost it all" agitated, but "Dang it" ::refresh:: agitated.