Need a good webmail program

[web123s]

Anyone know of a good program to start a Hotmail, Yahoo Mail style site?

I'd prefer something Linux based but could do any unix or windows.

Thanks in advance for the help!

[soldierdog]

If your looking for automated signups I'm don't know off hand but if your looking for a good webmail system without that feature, squirrel mail is great. Just do a search at www.freshmeat.net and there should be a few options.