in backend/app/model/Email.scala [31:37]
def withRfcValue(id: String): String = id match {
case _ if id.startsWith("1") || id.startsWith("2") => Urgent
case _ if id.startsWith("3") => Normal
case _ if id.startsWith("4") || id.startsWith("5") => NotUrgent
// cover cases where clients have written the priority as a string
case _ => id.toLowerCase(Locale.UK)
}