Magic Letter is a form of communication in the Magic world.
At first sight, it looks like a normal, ordinary letter with a wax seal on the envelope. When the addressee performs a certain circle motion around the wax seal, they release a small, magical hologram of the sender. Magic Letters don't need special items for reading, so they are more convenient and comfortable to use.
- ↑ Fairy Tail Manga: Chapter 15, Page 3