is it not possible to say "nekdo poslal tuto zpravu do nasim manzelkam"?
1) Do is used with genitive, not dative.
2) Do means 'into/in' (a place, a location) or 'until/till' (a point in time).
Why is 'Někdo poslal našim ženám tento vzkaz' not accepted?
Because no one has reported anything with "vzkaz" yet.
So there is nothing wrong with my version as such?