Abuse Policy bothers our social networking website

We spoke with more then 20 hosting providers and did not get helpful answer. Maybe we did not bring our idea clearly? We lunch social business network where users send messages, invitations and get email notifications and etc. From real situation: A user scanned his email through our system on the website and then selected “Invite all you contacts” and sent invitations to all he had on the list (240 emails). After that hosting provider got abuse letters and finally shot down our website. There are many social networks websites which allow users to invite contacts. I did it with facebook, myspace and other. But in our case all hosting providers they say “If we get abuse letters to much we shot down your account”. We are interested that users would invite their contacts to join network, but we are going to risk to be shot down because of Abuse Policy. Is there anyone who met that challenge? Is there any idea what to do?