As evidenced by my recent tutorials on Thunderbird I had been using Thunderbird as my primary email client for about a week. Just yesterday I switched back to Gmail here is why. First of all as a client Thunderbird is great but it's not without it's quirks little things here and there that only an advanced user would really notice don't work as expected. Secondly you cannot help but feel with the proliferation and popularity of Firefox that Thunderbird is the bastardized step child of Mozilla. Fairly recently Thunderbird was moved to it's own company and funding sources at www.mozillamessaging.com however development has still been slow. Beta 1 of Thunderbird 3 just became available after the Alpha 2 being out for several months. Thunderbird 3 looks to have significant improvements however you have to wonder how long it's going to take with the current release track they're following. The current stable release, Thunderbird 2 feels like it's stuck in 2005. For me the biggest hurdle to overcome was having my email tired to one computer. I thought I had overcome that an talked myself into leaving email on my primary computer and going email free on my laptop but I just couldn't do that. In today's day and age people need their email accessible from where ever, whenever especially webmasters and business people who need to keep in touch and be alerted to server issues via email 24/7. Sure there is IMAP but that's not without it's own flaws and aggravating 'features' Spam control was an issue. Gmail just takes care of spam, even running Mailwasher & Thunderbird spam quickly became a headache. Personally I think part of the reason for stagnation in the development is that potential developers realize email clients are quickly becoming a thing of the past with the proliferation of webmail clients that do so much more than just email people are happy to use them and have their email accessible from anywhere. Outside of clients like Outlook which do much more than just email, I think clients are quickly becoming a thing of the past.