Free Newsletter plugin suggestion

Hello team,

I have been asked to create a newsletter system that should send messages to less than 500 users.

I am having huge difficulties on finding a simple plugin that can suits my needs well.

1. Must be free (the use would be very modest and is not for lead generation)
2. Must have a customisable form where I can add custom fields and drop downs
3. Must be able to send emails to a list of user based on filters. These filters are basically the answer of the users from the sign up form.

To give you a quick example, my form should have a dropdown menu saying “Type” and the option should be 1,2,3,4 and so on. I’d like to be able to send a newsletter or a mass email only to those that selected option 3.

The most important feature is number 3, any suggestions?

Thanks!