Any APRS client that has messaging capability also has the capability to send internet e-mail. Receiving is another issue however, due to FCC regulations. An internet or RF-connected APRS user can send messages to any other APRS user though.
To send an internet e-mail, one method is as follows:
- To: "EMAIL"
- Body of Message: "firstname.lastname@example.org Here is my text message."
A server in New Jersey will pick up that message, send it to the internet e-mail address listed at the beginning of the message text, and you should get a response shortly back from the e-mail server letting you know whether the message was delivered.
There are other e-mail servers as well. Perhaps people will populate this page with more info so that they can be documented in one place.