Because one size does not fit all. I tried Gmail and other mail clients, but I've been in Thunderbird since 2007 now. I love the speed. I use it for work emai

Because one size does not fit all. I tried Gmail and other mail clients, but I've been in Thunderbird since 2007 now. I love the speed. I use it for work email. I like the tagging. I like the speed. I click and email opens. It doesn't matter how slow my connection is right now. It's easy to backup to an external hard drive. When my browser crashes, my email does not. I like how the folders work. The spam filter is awesome. Buy mostly, it just feels like home to me. I don't know how to explain it, but I love being in Thunderbird, and I just can't operate without it now.