You have a better control with GenServer, while Task is a process meant to do something, then die.
But if it is just to send an email, You could just spawn a process, then You could ask why a Task over a Process?
One day You might decide to have a better control, a better error handling, or just support back pressure… You might send billions for Christmas, and less the rest of the year. In this case I would not choose Task.
