This makes it easier for the reader. Sometimes letters to local newspapers are used to thank people who helped find a lost dog or help after an accident; but who did not leave their names.
See the Peer evaluation form for an example of how this can be done. They make a good follow up exercise after receiving presents or going on a visit.
Remind students to use closings and sign their names. But care should be taken to make sure that all the questions in the original letters are answered. It's how we say goodbye. Your class has just been out on a school visit to a farm.
What are the problems of living amid all that snow and ice? It's easy as 1,2,3!
These would be delivered to the second class for answering. Always use your best and clearest handwriting. London, U.