It seems like Mailchimp Omnivore is hungry! Many people have contacted me recently in relation to not being able to send from their Mailchimp account as Mailchimp has disabled their sending. This occurs once a list has been imported and Mailchimp determines that the list contains email addresses that will cause a high rate of complaints, one or more email addresses are honeypot (spamtrap) email addresses and so on.
Once your list import is complete, Mailchimp will send you an email with the subject Mailchimp List Import Complete with the following message:
Our automated abuse prevention system has predicted a high bounce, complaint, or spamtrap rate for this list. As a result, you cannot send to these contacts at this time.
To send to the list again, remove these new contacts or undo your recent imports. After these contacts are removed, you can send to your list.
Once you login to your Mailchimp account you’ll also notice a red bar across the top of the screen with a similar warning.