[cupofpython]

you might have an easier time splitting up send and receive into separate managed things instead of looking for one system to do it all over SMS

_SEND_

You can send an email over SMS I believe by texting the email address.

So you should be able to set up a server to process emails you send to a specific address and trigger commands in response to it. the triggers would need to be set up in advance, but other than that you should be able to do anything normal

_RECEIVE_

For receiving SMS - I am not sure tbh. You could use Twilio, but it might be overkill. I would jsut make sure whatever solution you use doesn't get automatically blocked by the ISP. I am not sure the proper way to flag something as wanted / intended