I don’t believe the Airtable team has added an App for this yet. But if I was trying to do something like this, I’d use a service like Lob.
They are a third-party API that will programmatically mail physical postcards to your customer for you. All you have to do is make a proper call to their API.
The easiest route to integrate the two would be using Zapier.
The trigger in Zapier would probably be whenver a new record enters a view in Airtable.
The action in Zapier would be sending a postcard to that particular customer.
If you didn’t want to use Zapier, or Zapier wasn’t an option, you could also use either the Airtable Scripting App or create a Custom App on the BlocksSDK that could do the same function.
That’s obviously simplifying it a bit, but I think you could set it up fairly easily.
Feel free to send me a DM if you have any specific questions while trying to set this up.