RegEx inside a Google Script FOR that skip values

Question

I can't understand why is skipping 2nd and 4th array position giving to the variable match a "null" value.

  // regex to catch email
  var regExp = new RegExp("[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,6}", "gi");

  var emailArray = Array("foo + bar tes+T@gmail.com", "some + text test2A@gms.com", "another + text test3+d@dddd.com", "text + text testtest4@ggg.com");
  for (var h = 0; h < emailArray.length; h++){
    Logger.log("The value was: " + emailArray[h]);
    var match = regExp.exec(emailArray[h]);
    Logger.log("I found: " + match);
  }

Results:

match: tes+T@gmail.com
match: null
match: test3+d@dddd.com
match: null