Shadowsands

Postgirl Ginger is on an important mission when she loses her memory to heat stroke and desert fever on her way. The only reason she knows she's a postgirl is the fact that she has cat ears and can transform into a cat, the tell-tale sign across all kingdoms of a person belonging to the Elite Postal Service (EPS). Meanwhile, Cerin, the son of the Sultan of Shadows (SOS), is sure something big is going on in the Shady Tower. Something concerning shadow magic. At least his father, the evilest of them all, is off warring with the snowy region of Icecall to the north. But this will only delay the Council's plans for so long... When Ginger finds her important letter and delivers it in sandy rags to Cerin, they must both work together to figure out what is going on in Shadowsands (Ginger as a friendly postgirl and Cerin as the feared son of the person who has Shadowsands on its knees) and hopefully put a stop to it.
(I know the description sounds a bit cheesy, but it's not final as I have no idea where this story is going. I just thought a friendly postgirl and an isolated guy who sends everyone cowering in fear because of his father would be an interesting duo) (Also, I don't own the cover art)