Migrate the contacts that you have collected in Mailchimp to Omnisend with ease as there's no need to export them first and import from a file later. Built-in integration enables one to skip the selection of attributes step.

Before you start

You can import the following fields from your Mailchimp contacts lists to Omnisend:

  • Default fields (First name, Last name, Phone, Address line 1, City, State, Zip code, Country code). During the import, these fields will be mapped with the fields in your Omnisend subscriber profile.
  • We will also transfer your contacts' statuses for the Email channel: Subscribed, Non-subscribed, and Unsubscribed.
  • Stats (average open rate, average click rate). These fields will be added to the contacts profile as a custom property with a prefix mailchimp_[stats_name]. These metrics can vary from 0 to 1. If you multiply the number by 100, you will get the percentage of the emails your customers have opened.
  • VIP and all other tags - will be imported as a contact tag. Just note, spaces in the name will be changed to underscore (_) symbol, and any symbols we don't support, such as #$%^&* will be deleted. If we already have the same tag name in the system, the system will automatically add numbering, ex: tag_1, tag_2, etc.
  • Language property. It will be imported as a custom property, and it will be named "language" (without "mailchimp_" prefix).

Any other contact data additional to default properties and tags will be imported as Custom properties to Omnisend. 


Since the Birthday date (MM/DD) has a different format than the one from Omnisend (YYYY-MM-DD), it is imported as a custom property. If you want this information to be used for the Birthday automation, you need to change the format of the date in the file and upload it manually. We suggest adding any year for the date field, as it won't influence the automation performance.

Note, the default date-added field will be set to the date when this contact was added to Omnisend. The date when your contact was added to MailChimp will be transferred as a custom property.

How it works

Before you can import your contacts to Omnisend, you should generate an API key in Mailchimp and copy it. Then, you need to paste this key to your Omnisend account. 

To initiate the Import from MailChimp, go to Audience > click Add Contacts > find Mailchimp and click Open wizard.

The import process will consist of the following stages:

  1. Enter API key
  2. Select lists
  3. Organize
  4. Review

Let's go through each of these steps in greater detail.

1. Enter API key

2. Select lists

After you paste the API key to Omnisend, we show all of the Lists you have created in MailChimp.

If you have more than one list in MailChimp, you may initiate different import processes for each of them. On the Organize stage, you can add different tags, therefore filtering your contacts to different Segments in Omnisend.

3. Organize

Add a Tag

When you import contacts, Omnisend adds two tags automatically:

  • source: mailchimp import;
  • imported from mailchim on DD/MM/YY HH:MM:DD, for example: imported from mailchim on 27/03/20 09:57:05am.

Apart from the tags added automatically, you may also add one manually by selecting one of the existing tags or creating a new one.

Create a Segment

Even though you can always create a Segment based on the tag added manually, you can also choose to create one automatically. The segment will be named after the type of import and date of import - "Contacts imported via <manual_import_type> on <date_of_import>”. 

You can find the imported Segment by navigating to Audience > Saved segments.

Trigger Segment based automation

If you have any Segment based automation enabled, you may choose to trigger it for the contacts added to the Segment. 

4. Review 

In this section, a summary of the file is shown. You can see the number of contacts and what tags should be assigned. 

That's it! You will be brought back to the import tab where you will see the progress of your import. Click Report to see the detailed statement on how many new and existing contacts have been added as well as how many good/bad emails/phone numbers were found.

Keep in mind that it might take some time to import all contacts, as Mailchimp limits on how quickly we can pull your data from them.

Default & Custom

The list of the fields you can map consists of the default and custom properties. We always recommend mapping as many properties with the default fields as possible. Therefore it is better to initiate the manual import and assign some of them manually.

For example, instead of importing the Phone number as a custom property, you may import it from the file and assign it to the default field in Omnisend. The same goes for the Birthday date. 

Check this article for the instruction on the manual import of the contacts.

Manage your Segments

Although the number of properties we can sync from MailChimp is extensive, the information available to MailChimp is more comprehensive. Of course, you can make some conclusions about your customers' engagement with the average open rate and average click rate; you still can't view this information on the time scale.

Therefore, it would make more sense to create a Segment of engaged contacts in MailChimp and then transfer it to Omnisend. Here is the list of the Segments we would recommend to transfer:

  1. Engaged contacts & Loyal customers
  2. Inactive contacts
  3. Any other Segment you find appropriate

After you export these Segments from your MailChimp account, you may import them to the corresponding Segments in Omnisend.

Engaged contacts & Loyal customers

When you are starting with a new ESP, like Omnisend, you need to work on your sender's reputation. The best way to improve it is to send your emails to the most engaged contacts only. We've already mentioned that you can create such segments in MailChimp and transfer them to Omnisend. However, you can also use the mix of the information synced from your store, transferred from MailChimp, and collected with Omnisend.

Let's decide on the criteria we can use to estimate whether your contacts are engaged or not.

  • The customer has purchased a product in the last few months
  • The customer has opened the email sent with Omnisend in the last few months
  • The customer has opened at least one email sent with MailChimp

All of the rules stated above should be applied to the Subsubscribed contacts since those are the only ones that can receive any emails from you. In addition to that, we also want to exclude the contacts that were added to your list recently. There is a chance that they didn't have enough time to engage with your content, or you didn't send any emails to them yet.

Therefore, we are adding two more rules: 

  • The customer is subscribed
  • The customer is not added in the last few months.

Alright, let's try to combine these data.

It looks a bit complex, but let's try to understand what we've done here. 

The first rules Segments the contacts that are subscribed to my marketing.

The second rule is more complex, and it segments the customers that have placed at least one order in the last 6 months OR have opened at least one email sent with Omnisend in the last 6 months OR have opened at least one Email sent with MailChimp OR were added more than 1 month ago.

The first and second rules are combined with AND operator since we not only want to see subscribed contacts but also those that showed at least some activity. All of the filters we added to the second rule are connected with the OR operator since it should be enough to open at least one email or to place at least one order to be added to this Segment.

Important! Be careful with the average open rate transferred from MailChimp. This data doesn't indicate whether your customers engaged with your emails recently or have opened at least one email sent a few years ago. To constrain this Segment, you may try to specify the percentage of the emails your customers have opened. For example, mailchimp_avg_open_rate is more than 0.1 will add customers that opened at least 10% of the emails sent with MailChimp.

Inactive contacts

While there are no strict regulations for the Segment with Active contacts, those that are indeed inactive should be removed from your Omnisend account. You can always start from checking your list with some validation services, like Mailgun, Neverbounce, myEmailVerifier, Quickemailverification, etc. Once you remove bounces, you can also create a Segment based on the information we've collected, and either delete those contacts either unsubscribe them.

Here is the example of such Segment:

As you may see, only those contacts that didn't open any emails and didn't place any orders will be added to this Segment. We didn't add a rule for the average open rate transferred from MailChimp since only those contacts that have this property would be added to this Segment. 

If something is not clear or your need some recommendations, feel free to jump on a chat with our Support Team or send us an email at support@omnisend.com.

Next Steps

  • Start working on building an outstanding sender's reputation with Omnisend by following our recommendations regarding the content and following the warm-up plan.
  • Overtake our idea of contacting your customers through the communication channel they prefer. 
Did this answer your question?