IHN is an acronym for "In His Name" which some people tend to use at the beginning of email. Those people believe that they should start each piece of writing with the name of God. According to Qur'an when Solomon wanted to write a letter he used the Basmala phrase. It is believed that Muhammad started all of his letters with the Basmala. They believe that other prophets also started their written works, as well as their speeches, with the name of God. Using IHN at the beginning of an email is a way to say "Bismillah" or "In The Name of God".