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How to solve MailChimp’s Omnivore Warning issue.

10 min read

By now you have heard of MailChimp, and if you have tried it, then likely you have heard of Omnivore. Omnivore, it’s the abuse-prevention program, and it could make it a bit more difficult to reach 100% delivery rate on your email campaign.

Omnivore warning

The image above shows how the issue looks like. This is the infamous Omnivore warning.

MailChimp uses this program to reduce, and try to eradicate, suspicious activity from malicious email addresses. This also could be caused by bad URLs and rather suspicious keywords. It’s a software that is considered necessary but, if the rules of operation are not clear, it can be a little pain for your market campaign.

Here we will cover in detail what Omnivore is, how it works, the type of warnings it can give you and what to do. In addition to this we have incorporated a brief guide on how to verify your email list and prevent future Omnivore warnings.

What is Omnivore?

Basically, it operates as a filter so for now let’s consider it one. It uses an artificial intelligence system to scan every email list you give MailChimp. It’s IA is likely made using neural networks.

It looks for addresses that are likely to generate complaints, high bounce rates or blacklisting. Depending on how many of these you have in your list you’ll receive an Omnivore Warning. This warning forces you to solve the issue before proceeding.

The software has been implemented since 2008 and the algorithm changes regularly based on feedback from the users.

How does it work?

The algorithm reads every list you upload and assigns a level of risk to each email, if the risk level goes beyond a certain threshold MailChimp’s system won’t deliver to those addresses. Incidentally the system won’t tell you which address in the list are the problem. This forces human input and effort to make sure you are certain of what you’re doing.

Why is Omnivore necessary?

Omnivore is done and implemented with the best reasons at heart, but MailChimp needs to protect its reputation. This is also part of what makes the platform a good one. If you get the reputation of a spammer it could cause you a lot of grave problems. Emailing systems can and will be blocked by the ISP if it deems it worth it.

What is an Omnivore warning?

Is the message MailChimp sends an user when the email list it uploaded is not clean enough. Omnivore can also be considered the standards your list has to accomplish in order to be accepted by MailChimp.

They usually look like this.

omivore warning example

These warnings can be sent via email or within the MailChimp dashboard. Once you get one you are forced to take action.

One way to solve this problem is by using a email verification service before taking you list to MailChimp.

What does trigger an Omnivore warning?

Luckily MailChimp has provided the list of the elements of a email list that will trigger Omnivore.

Omnivore searches for stale email addresses.

This is a list of addresses that have not received emails from you in a long time. This stale list will have a higher rate of bounces than a more updated list.

This is because stale addresses are likely to become inactive. For instance, people forget they have them, leave companies or simply will reject your emails.

A database can decay at an alarming rate of 23% per year. Keeping your data up to date should be, and is, a priority in most cases. This effort has to be made by a person and is hard work for the majority of cases.

Omnivore looks for unfamiliar addresses.

Whenever you import a new list to the MailChimp system Omnivore enters in action. This time it’s checking for addresses that you haven’t contacted before using MailChimp.

New addresses can come from anywhere. People that just recently signed up for your news letter or from people that come from other campaigns.

In this case, is better to bring small amounts of new addresses into the system. Exceeding a certain threshold will trigger a warning from Omnivore.

Omnivore searches for spam traps.

Omnivore scans every new list looking for spam traps, in the email addresses that is.

These traps are implemented by the ISPs, third parties and other organizations to identify out date lists. They can also use them to generate abuse complaints. Often enough these addresses don’t belong to subscribers and are used to see if you are a spammer.

Better to pay attention to the warnings provided here than to have your emails blocked. With that in mind let’s see the difference between a warning from Omnivore and an account suspension.

Omnivore warning vs Account suspension.

account suspension due to omnivore warning

That’s what an account suspension looks like. Beyond a warning MailChimp can suspend your account for one of the next reasons.

Issues with recent campaigns.
Unclear list collection process.
Being signed up with a free email account.
Violation of terms of use.

If that is the case, hopefully is not, the MailChimp support will contact you and try to help you. Keep in mind that if you’re suspended three times in six months Omnivore will close your account permanently.

Better safe than sorry so don’t disregard Omnivore’s warnings.

What to do when the warning strikes.

First of all, the most important, do not ignore them. Your email campaign will be put on hold until you resolve it and believe me it won’t go away on its own.

Clean your list and upload it again.

If you have just uploaded a list to MailChimp and Omnivore just flagged it. Then you need to remove it and clean it from anything causing the issue. Removing it from MailChimp’s system will allow the rest of your list to be in active use.

MailChimp is a very diligent platform when it comes to protect its reputation, and that of the users. It’s known for delivering effective email campaigns, the system is very well suited to prevent spam mail.

mailchimp omnivore issue

How to prevent a warning from Omnivore.

There are various ways to prevent a warning and make sure you have a clean list. This in turn will help you reach as close as you can to 100% deliverability. Follow on for the tips.

Get double opt-ins.

When a person signs to receive emails from you, you should put them through a double opt-in process. Basically, double check that they want to join in. This could be done via a verification email and the process finishes when the click on a link in the email.

This is a safe method to ensure that you have a rather clean subscriber list.

Be aware for role-based emails.

Yet another way to help you prevent an Omnivore warning. MailChimp is very serious about this, and treats role-based mails as a sure sign of a dirty list.

A role-base mail is any generic address without a name. They are usually ones with a very high bounce rate. Omnivore allows few of them in any list it receives. This is one of the likely reasons why you would receive a warning.

Careful with third-part lists.

Omnivore is very careful when it comes to high risk and its verification, especially about spam mails and addresses. If you get a list bought or “borrowed” from third parties is likely you get old addresses. These can be identified by Omnivore as spam.

Doing the acquiring yourself is better and this way you make sure to remain in control of the lists you upload. Keep a clean and updated list and Omnivore will be no problem for you.

How to verify your list and avoid Omnivore warnings.

Get as many double opt-ins as you possibly can.

Marketing requires you to know about this and handle it very well. So, practice this and get as many as you can. In doing this you will be reducing the number of people that signed by accident.

In turn this will also help MailChimp discard the possibility of role-based addresses. At the end of the day is better to use double opt-ins. Experience tells us that the are not only safer but also prove to be a money saving habit.

Use a cloud-based service for cleaning.

If you have a small list or a long one, it doesn’t matter. Is important to have a service to help you validate it. This means formatting, verifying and such tasks.

Use your most trusted service for this.

What to look for when it comes to email validation.

Basically, you want to be sure that the company doing this won’t delete any address. It must return the list with added information, like the status of an address.

Using a cloud-based service is better if what you look for is precision. This way you are sure that all the addresses will be validated.

If you like doing things yourself.

You can always make a list in excel and organize everything by title, this way you can detect any role-based addresses, free ones or old ones.

Keep an aye out for addresses missing the “@” and duplicated names.

Email list scenarios that you have likely encountered by now.

New addresses recently uploaded.

You have a new list, and it comes with many new addresses. You uploaded and the *BUM* Omnivore sends a warning. The warning basically says that some of the new addresses are invalid, and therefore, your new list is also.

So, take a few steps back, clean your list and upload it again but maybe without a few new addresses, at least temporarily.

Old lists with bad data.

It is known to happen, you re-use an old list, or just forget to update one. This could result in having a bad list full of addresses that are no longer being used. These addresses will likely be the reason you get a warning from Omnivore, as they are seen as invalid.

Luckily there is an ease fix. Just confirm the information on the list and reupload what’s left of it.

Mysterious data.

It happens that every now and then accounts are shared and you may not be entirely sure when a subscriber was imported. If this case presents itself, you have to segment and delete the addresses you suspect to be the cause of the issue.

New and old lists are subject to this, so be careful.

Spam evolves, so it should email verification.

Checking an email address is often a fast process, especially with a validation service. Being fast or slow can make a great difference for the approval of your list by Omnivore. This translate into a higher chance of a successful email marketing campaign.

If your data is one the most important assets you have, don’t play around with it. Use a trusted and well recommended service of validation. A reputable and professional one will help you get nearer of that desired 100% deliverability.

These services can be expensive or cheap, this will depend on who you chose for the task. The fee can usually be paid in two ways. Paying as you go or based in a subscription plan.

If you feel like it then, why not use EmailVerify? They're a very responsible and hard working team.

using mailchimp's omnivore can help with delivery issues

What you shouldn’t do when you get an Omnivore warning.

I know is tempting to try and solve it by yourself, using a blind-cc to every address and then sending it to yourself. It is a way to see where the bouncing happens and then remove the undesired addresses.

This is not such a good idea. Massive blind-cc will likely have repercussions on your reputation with your mailing service, it can also bring undesired attention to your IP. This could endanger your ability to send emails, so please don’t do it.

What Omnivore doesn’t do.

Omnivore is just an algorithm; it’s not going to answer your queries. Try a MailChimp support team member. If you get your account suspended or warned, a member of MailChimp’s team will review the problem.

In the end.

Email campaigns can, and often are, a crucial part of online marketing. For the campaigns strategy to be successful you need the emails to be delivered without problems. Omnivore is a tool that, if you understand it, will help you do this with a healthy reputation.

If you’re using MailChimp you know about this. And for the foreseeable future you can count on Omnivore going trough more changes and improvements. It will learn and is not always going to be a problem for you. Likely it will be the solution to reputation problem it has always been, just a little better at what it does do. Hope that you find this clear and enlightening, best of luck in future campaigns.

mailchimp omnivore issue