When you use the SMS feature, we're not able to use functions from iMessage. These SMS messages are not send via iMessage, so they won’t show up in your iMessage history. Apple is, unfortunately, rather strict with these types of things. That’s why we’re forced to use an external SMS gateway to handle the Auto Send messages.
For Scheduled Premium we have a feature that allows you write and schedule messages that get sent automatically through iMessage, WhatsApp, Telgram and Email. Please read more about this feature here.
So what happens to messages in reply to my Auto Send number?
When people reply to your Auto Send message, you can find these replies in 'Received'