One text field can contain only one data. So, you need another text field to achieve that. if you don't want to show the multiple emails, you can use hidden fields.
{{ Form::hidden('email[]', Input::old('email1'))
{{ Form::hidden('email[]', Input::old('email2'))
Or you can use select. Laravel allow array data if use select field.
For example:
{{ Form::select('size', array('L' => 'Large', 'S' => 'Small')) }}