In the end, Thunderbird is a decent mail reader, but I question the need for it, because webmail systems like Yahoo Mail and Gmail have gotten so feature rich—they do pretty much everything Thunderbird does. And for businesses, Thunderbird offers nowhere near the calendaring, scheduling, and reminder features of Outlook, and it doesn't support the universally used Exchange server, which you can access right in Snow Leopard's mail client or in its own Web interface.
If you need a free installed mail client that handles multiple accounts, I actually prefer Windows Live Mail, which is slicker, even more intuitive, and much more versatile at handling attached photos. And Mac users are quite well served by that platform's Mail app. One group, however, that will just love Thunderbird are Linux users—after all, they have no better option for an installed mail app.
Price as Tested: $0.00 Direct
Type: Business, Personal, Professional
OS Compatibility: Windows Vista, Windows XP, Linux, Mac OS, Windows 7