I have used Yahoo Mail for many years, but recently I have been phasing out that account in favor of Gmail. I just started using Yahoo's new beta version, and I have to say it is a big improvement. I am starting to use that account again.
It is sort of like using an online version of a traditional email program, with your boxes on the left, a list of messages on the top, and the message you have selected on the bottom.
I just received a message with some Chinese in it, though, and the Chinese came out garbled. I went to switch the encoding in my browser, and lo and behold Yahoo Mail was telling me to switch the encoding via an option on the page! A very nice way to get around the problem that Gmail had for a while. With Gmail you have to select "View Original" and then change your encoding. Yahoo does it for you--theoretically. Unfortunately, I selected my appropriate flavor of Chinese (Big5), and it still came out scrambled. I will have to mess around with it to see if it isn't a problem on the sender's end.
Gmail has most of the kinks worked out by now, and I have few problems with mixed-language messages and attachments now.