My buddy has a Samsung through Sprint. I have a Droid through Verizon. The problem is, starting yesterday, he can't receive any calls or texts from me. He can send me texts and call me, but not the other way around. He has no other problems with receiving calls/texts from anyone else, just me. The only thing he thinks it might be is he accidentally marked one of my voicemails as "spam" the other day. Would this be why? If so, how does he reverse it? Thank you in advance.