*If the cell phone receiving the SMS has another application similar to this feature (such as Google Voice) then they may not be able to receive the SMS.
a- The cell phone that you sent the SMS message to will receive a message from Yahoo telling them “A Yahoo! User is trying to send you a text message. When it arrives, select ‘Reply’ to continue the conversation”. This confirmation from Yahoo will only occur if it is the first time receiving a text message from Yahoo.
b- Accept your Yahoo SMS, if you sent it to your own cell phone. Follow the instructions from Yahoo. (Some phones will be able to automatically reply without selecting it). The recipient will view the message as being sent from your Yahoo user name (the ‘from’ number will be one from Yahoo’s servers and not related to anyone’s cell phone). Time to receive messages may vary based on phone service and type.