1) App should be able to send emails with a specific frequency ,ex:
from 1 to 100 emails (and random from 1-100), per time frequency we select(and should be able to select an random time from 1 sec to 60 min ,and how many emails per frequency
2) App should send failure delivery to a specific email (like report that email is incorrect )
3)App should be able to send email with text and imagine ,and gif/flash content /text
4)App should be able to send emails to unlimited nr of emails that will be added manually in a specific box(or file) ,emails should be send in bcc.
5) Client should have possibility to unsubscribe, and his email have to be moved in diff list or get notified about that .Or we could have a button implemented that by clicking it client could send us a notification to us .(or you could implement the button we already have )