As a beta product, this one is very usable now. While I've had some startup problems when using it with Object Desktop's Tab Launch Pad, ICE has never crashed on any system I've used it on. There are even conversion programs available for PMMail and La Mail address lists and mail folders.
Installation is a snap.
Just unzip the .ZIP files for the main program and, optionally, the spell checker and thesaurus in the appropriate directory, connect to your Internet service provider, and start the program. ICE will automatically configure itself to the settings needed for your ISP and display them to you so you can verify they are correct. Once all of the features are completed and available, ICE promises to offer the most function in a mailer I've seen at this price level. Open a mail folder, and a tab is added for it in the notebook. Close the mail folder and the tab goes away.