They have your number so you can tell them to include it in their sms when they are sending it to you. Or better yet their own number. Your spamfilter might let such messages through. Or at least name or something. Anyway you they have to provide some details about themselves in sms so you can know who contacts you.
Thinking further voicebot to filter out call spam also would be nice. ;-)
Thinking further voicebot to filter out call spam also would be nice. ;-)