I don't think anyone explicitly mentioned that you will need a computer to make all this work onboard. The SSB receives the info and then the Pactor modem sends it to your laptop, where specialized software allows you to send and receive text email, receive weather faxes, and download GRIB weather files for viewing. Jim Corenman's Airmail client is a widely used program for doing all this. He's written a pretty good description of how it all fits together at
Pactor Primer.
To have access to email, text weather forecasts, and GRIB downloads, you need to sign up with a service such as
Sailmail or Winmail. They operate a network of shortwave radio stations located all over the world.