The very first magic law practitioners were elementals. When Mythic law practitioners began to surface, they were considered heretics.
...
"Of course, they don't read our letters," Quinn told Hade as the two of them made their way to the Magic Science class.
"If they did, it would be a huge invasion of privacy."
"Okay," Hade nodded. He just wanted to make sure.
"Besides," said Quinn.
"Most of the kids here have some pretty powerful backgrounds. It would not be in the School's best interests if they tried to know too much about their students.
"But, if you are still worried you can just imbue a magic seal onto your letter," he suggested.
Magic seals were a preventative measure practitioners used to keep their messages secret.
If a seal was broken before the letter reached its intended destination, the recipient of the letter would know that it had been tampered with.