I'm in one of these countries. If they have a cause that cannot be legally used to terminate an employee, they just look long and hard for any other misdemeanors and fire them as fast as they gather any plausible "evidence". Creative types can also actively put an employee into a checkmate, i.e. a position where no move or any move is a fireable offense.

In this case it could be as simple as identifying any part of that email as a defamation.