I'm trying to use net-enabled Arduinos to instrument some stuff around the house. For example, I'd like my dryer to text me when it's finished. So it would be useful to have a local mail server on a Linux box, that the Arduino could communicate with (unencrypted) using SMTP commands. The server would forward the Arduino-generated message to email@example.com, eventually resulting in my receiving the text. I'll never need to receive email with this server, and I don't want to have the Arduinos communicating outside my local network.
Is it possible to set up a mail forwarder like that, without having a domain name?