Email Exchanges in the classroom

Email exchanges in foreign language instruction seem like they would not serve any purpose but in reality they are very useful in the learning process. The exchange of emails between a native Italian or Spanish speaker with a native English speaker not only help each person learn aspects of the other language ( verbs,vocab, phrases etc.) but also learn how native speakers use these things in a natural way, without the proper, rigid instruction of the classroom. Many foreign language teachers especially at the hi school level do not do this because they feel it impedes the proper instruction  of language but in my opinion, it is good to teach both proper and improper ways of speaking and utilizing the language, especially when students for the most part will need to know improper / simple ways of speaking when they travel to the country with the target language. Aside from foreign language instruction, email exchanges between people in different schools, states, countries in other subject areas can be very useful as well.  For example, in math or English, email exchanges about how to do a problem or analyze a text can teach a student new ways of looking at approaches to the problem they may have never thought of before.