The movie owes its existence to a real-life body horror that Cronenberg experienced when his wife of 43 years, Carolyn, was diagnosed with a cancer that ravaged her body and ultimately took her life.

A horror film set in the 1980s with a synthesizer score is nothing new. But “Dead Mail,” the second feature from directors Joe DeBoer and Kyle McConaghy, manages to find a fresh angle on the nostalgic ...