Lovely software, "the" best webmail application I have ever used...
Clean and easy to understand interface, customizeable via CSS, even works in Safari.
However, it has huge problems while connecting to servers. I had to empty cache and delete cookies several times, not to mention dumping the database a few times. That's why I gave it a three. (The reason it recorded a two is because my damn mouse skips a lot and I didn't notice I hit 2 until I viewed the results!)