GMail is one of the most used e-mail systems across the globe. Given that there are about 7,000 languages spoken around the world, being able to understand each other’s communication is very important. Hence Google’s integration of the Translate service into GMail.
In the Google Labs tab in GMail, there is a feature called Message Translation. If you receive an e-mail in another language with this feature enabled there will be an option where it says “translate message to:” or an option to “change language.”
The feature was announced on the Google GMail blog.