3'-exoribonuclease that has a preference for poly(A) tails of mRNAs, thereby efficiently degrading poly(A) tails. Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs (By similarity). Exonucleolytic cleavage of poly(A) to 5'-AMP. Belongs to the CAF1 family. The predicted gene has been split into 2 genes: At3g25430 and At3g25440.