-

#! /usr/bin/osascript -l JavaScript

Mail = Application('Mail');
release = Mail.accounts.byName("Exchange").mailboxes.byName("release");
messages = release.messages();

histo = messages.reduce(function(acc, msg, ix, arr) {
  from = msg.sender();

  if (!acc[from]) {
    acc[from] = 0
  }

  acc[from] += 1;
  return acc;
}, []);

for (var k in histo) {
  console.log(histo[k], k)
}