Translation:We received each others' gifts
If I heard the above, as a native speaker of American English, I would like it was as Catriona28745 thought, that I got the gift meant for the other person and they got mine. I would not think we each received a gift from each other unless "from" were in the sentence.
Yes, kupokea is 'to receive'. But this sentence uses the prepositional form of the verb meaning doing something for/to/at or on behalf of someone: in this case 'from' (and see discussion above). So, kupokea becomes kupokelea (to receive from), which in its turn becomes kupokeleana to show that they received the gifts from each other.