If you value your friendship or business relationship with the person you are messaging, then you would probably want to avoid teleflip. Neatly tucked into the recesses of their user agreement is a provision which permits them to "send messages through the service to any and all users" about "new or existing products or services to be offered by Teleflip." In other words, they receive the right SMSpam people.
E-mail fudged to thwart spammers. Transpose the c's and a's in my e-mail address to reply.