Hello there,
Thank you for writing in.
We wanted to reach out regarding the recent Omnivore alerts being seen in the account. Omnivore is our automated abuse prevention system, that flags any list imports or sends that may be predicted to experience a high bounce or abuse rate. When we notice lists that are flagged under these terms, it is usually because the addresses on the list may be old/stale (permission has not been active within 6 months).
It is important to note that this information is obtained by using a variety of algorithms and historical data associated with the addresses activity on a broad scale ( not just activity through your company ). So even though the data may have been freshly collected on your end, it's history could still run the risk of being old or invalid.
Typically the issues that cause this warning are the result of stale lists, lack of specific permission, or offline lists collection:
-Stale lists
http://kb.mailchimp.com/accounts/compliance-tips/when-email-addresses-go-stale
-Permission not being obtained before sending to a list
http://kb.mailchimp.com/article/ask-before-you-blast
-Offline lists
http://kb.mailchimp.com/lists/growth/opt-in-methods-for-offline-subscribers
If you believe you have proper permission to contact the individuals on this list by email, the following steps can be taken to reconfirm these addresses through a double opt-in form so that they may be added to your MailChimp account. We cannot support re-importing of these addresses moving forward.
http://kb.mailchimp.com/article/reconfirm-your-list
This should get things moving in the right direction. Please let us know if you have any other questions or concerns. We are here to help.