are all species immortal in valinor

[Mhoram]

Good catch Durelen, I offer two bits of letters that backup the interpretation:

But in this story it is supposed that there may be certain rare exceptions or accommodations (legitimately supposed? there always seem to be exceptions); and so certain 'mortals', who have played some great part in Elvish affairs, may pass with the Elves to Elvenhome. Thus Frodo (by the express gift of Arwen) and Bilbo, and eventually Sam (as adumbrated by Frodo); and as a unique exception Gimli the Dwarf, as friend of Legolas and 'servant' of Galadriel.

I have said nothing about it in this book, but the mythical idea underlying is that for mortals, since their 'kind' cannot be changed for ever, this is strictly only a temporary reward: a healing and redress of suffering. They cannot abide for ever, and though they cannot return to mortal earth, they can and will 'die' - of free will, and leave the world.

Letter 154 To Naomi Mitchison
25 September 1954

Foreseeing this in pan, the gods laid a Ban on the Númenóreans from the beginning: they must never sail to Eressëa, nor westward out of sight of their own land. In all other directions they could go as they would. They must not set foot on 'immortal' lands, and so become enamoured of an immortality (within the world), which was against their law, the special doom or gift of Ilúvatar (God), and which their nature could not in fact endure.

Letter 131 To Milton Waldman
probably written late in 1951

[ March 13, 2002: Message edited by: Mhoram ]