- Snape: "...we'll get the letter, you and me."
- Lily: "Really?"
- Snape: "Definitely."
- Lily: "And will it really come by owl?"
- Snape: "Normally. But you're Muggle-born, so someone from the school will have to come and explain to your parents."
- — Severus Snape explains to Lily Evans why her letter won't arrive by owl post.[src]
A special messenger is a wizard or witch assigned the post to deliver the acceptance letter from Hogwarts School of Witchcraft and Wizardry to Muggle-born people, explaining that magic truly exists, unless their parents have a wizard relation.