Google adds auto translation in Gmail.

If you often or occasionally receive emails in Spanish, Franch, Korean, Japanese, Chinese or other languages that you could not understand. It is probably the best features for you. Google adds the translator toolbar inside gmail this time. In the past, you may do translation in bitter steps such as copy message's sentence in google translator one by one and puzzle them up . Now, you can just need one mouse click to translate and get more accurate translation results. 

However, google achknowledged that this message translation technology is not perfect due to complexity of language's structure and semantics. To install auto translation feature in your Gmail, click on the "Setting" -> go to "Labs" tab -> enable "auto translation" ->save change.