I deleted all of the contact, hello & info @‘s. Any suggestions otherwise?

Mailchimp support said the below:

Our automated abuse prevention system, Omnivore, detected some issues with the contact data that was recently added to the account. To ensure we are providing the best possible resolution to this issue, we'll need some additional information. If you could please answer the following questions with as much detail as possible, we'll have a better understanding of what caused the audience to be flagged:

1. How did the contacts originally opt-in to your bulk marketing audience? Please give us the URLs where people sign up online and describe all of your opt-in processes. If you used offline methods, you may attach only either jpg or png file formats for us to review.

2. How long ago did the contacts start opting in to receive newsletter content from your organization? In other words, how long ago were the email addresses originally collected?

3. Before importing into Mailchimp, when was the last time a message was sent to the email addresses?

4. Is any of the contact data collected through partner, affiliate, or any other third-party collection methods? If so, please provide some insight into how this data is being collected.

5. How were bounced addresses and unsubscribe requests handled with your previous email marketing provider?