Neutrinos are particles with close to zero mass and neutral charge, which allows them to pass through matter without any significant interference.
The experiment, which took place at the NuMI particle accelerator, part of the Fermilab facility, sent the neutrino beam into the MINERvA neutrino detector at a distance of 0.6 miles in a cavern buried 300 feet below the surface. The message included the single word "neutrino" and was transmitted as binary code.
The implication is, of course, that there are other ways to send electronic messages than the plain email or text messages we are using today. However, the cost of send a neutrino mail is insanely expensive and includes a massive network of neutrino generation, neutrino acceleration as well as detection. And since MINERvA can only detect one in 10 billion neutrinos, the researchers have to send a huge number of them to spell out even the simplest words.
Still, at least we know there is an alternative for email.