I think things like BitMail, BitKey, KeyMail all seem super forgettable and boring to me.
I admit when I first heard Keyhotee I didn't know exactly what to think of it, I didn't know if the h was silent. I wasn't sure if it was supposed to sound like coyote. But I really like it now, much more than other suggestions. The name doesn't let people have preconceived notions about what it is or does, they have to discover it. You already have the word "key" in Keyhotee. Any name with "mail" doesn't do it justice at all. Once people learn it they won't forget it, and you can Google it and won't get results for anything else. It won't ever be confused with something from a competitor with a unique name. There is something adventurous and brave about choosing such a name.