What is a good web based email program?

Hi,

I am trying to offer free web based email from my web site. I want to do this with the same style as yahoo mail in which member can sign up for membership and receive a free email account.

I was wondering what software is available so that I can just install this onto a dedicated server. I have looked at hivemail but I am not ready to commit $160 for its license. Is there anything that you know is proven, either for license or for free?

I need to have administrative abilities to edit accounts (disk size, attachment size).

Thanks,
Roy

Two free projects:
The Horde Project
SquirrelMail

Horde used to only be a webmail app, but now comes with a bunch of other installable modules as well (address book, appointments, calendar, news headlines etc.) Right now, the webmail module of Horde is called Imp. See http://www.horde.org/projects.php for more details. All the horde modules integrate pretty well with each other and you can install only the modules that you want.

A good webmail system should also provide flexibility to end users as well as to the system admin. Taking into account that webmail will attract lots of users using it, a good webmail system should allow data compression when sending to the browser so that the time taken will be faster.

My suggestion is that you take a look at SocketMail (http://www.socketmail.com), its under $100 and also it has better functionalities and features. It also allow you to provide capability for you to do upselling (payable packages).

Cheers