About Omnivore

Each time a user imports new addresses or sends a campaign to new people, our abuse-prevention system, Omnivore, checks your audience for any email addresses you haven't contacted through Mailchimp yet. If you receive an alert that your audience has a very high predicted bounce or abuse rate, we'll disable sending to that audience until you remove the bad addresses.

In this article, you'll learn what can trigger this alert, and how to clean up your audience so you can get back to work.

What happened?

When you imported new contacts or tried to send a campaign, we scanned for addresses that haven't received campaigns from your Mailchimp account before. These addresses may be brand new imports, people who signed up through a form or a mobile app, or people you've segmented out of previous campaign sends.

Then, the Omnivore system checks to see how many of those addresses are likely to be spamtraps, or to generate abuse complaints and hard bounces. These kinds of addresses don't belong to active subscribers, and are sometimes used solely to catch spammers.

Omnivore is very accurate in predicting audience performance, and uses an algorithm to assign a level of risk associated with a group of addresses. When the level of risk is too high, we prevent sending to those addresses. Unfortunately, the system doesn't provide specific addresses that are likely to bounce, generate complaints, or hit spamtraps.

When you get this type of alert from Omnivore on your account, you won't be able to send to the affected audience, but the audience and its data are still intact. You can also continue sending to unaffected audiences in your account.

Why did this happen?

Omnivore monitors and analyzes audience data to help maintain the health of our email delivery system, and prevents deliveries that could negatively impact our sending reputation (and yours).

High rates of bounces, abuse complaints, or spamtrap hits can cause serious damage to your deliverability, and indicate an issue with audience collection or management processes. If Omnivore flags your addresses, look into how your audience was collected, and how it has been managed in the past.

Maintaining a healthy audience is a critical part of email marketing. We take the reputation of all our users very seriously, and tools like Omnivore help address any issues before a campaign is sent.

What should I do next?

The best way to resolve your Omnivore warning depends on when you last imported to your audience.

I recently imported new contacts.

If you've never had a compliance issue and you just imported a new batch of contacts, there's probably something in your latest import that caused the problem. To resolve this, undo the latest import and reconfirm the addresses.

I haven't imported any new addresses recently.

If you haven't sent to your audience regularly, your audience might contain old or invalid addresses. Reconfirm the addresses in your audience.

I'm not sure when contacts were imported.

If you use a shared account, you may not be sure when contacts were imported last, or how often they've been sent to. In this case, we recommend you use segmentation to remove the addresses that may have caused the issue.

Create a segment using Date Added | is after | a specific campaign was sent and choose your last successful campaign from the drop-down menu.

segment criteria fields show date added is after a specific campaign was sent.

Export that segment, delete it from your Mailchimp account, and reconfirm the addresses outside of Mailchimp.


If you were sending a campaign when you first received an Omnivore alert, that campaign will still have the Omnivore hold, but you can replicate that campaign to resend it to the modified audience.

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