Mailchimp ↔ Salesforce integration

Salesforce contacts and leads land in the right Mailchimp audience with their segment, and opens, clicks and unsubscribes come back to the Salesforce record

Sales keeps customers in Salesforce, marketing sends campaigns from Mailchimp, and between them sits an export file someone updates once a month. Mailchimp gets a stale list, and the manager calling a customer does not see that the customer clicked yesterday's offer or unsubscribed last week. The Mailchimp ↔ Salesforce pair keeps the chosen Salesforce contacts and leads in the right Mailchimp audience, and brings email activity back to the Salesforce record so sales sees it where they work. Below: what exactly moves, which scenarios we cover and which capabilities of both systems we rely on.

Request an integration System page: Mailchimp →System page: Salesforce →

What moves between the systems

Salesforce → MailchimpContacts and leads that match agreed rules in Salesforce, such as a region, industry or deal stage, are added to the Mailchimp audience with those values as tags or fields.
Salesforce → MailchimpWhen a contact's email, name or segment changes in Salesforce, the same subscriber in Mailchimp is updated, so campaigns go to current data.
Mailchimp → SalesforceOpens and clicks on Mailchimp campaigns are brought back to the Salesforce contact or lead as activity, with the campaign name and date.
Mailchimp → SalesforceAn unsubscribe in Mailchimp marks the Salesforce record, so nobody adds the person back to a list by hand and sales knows not to push email.
Mailchimp → SalesforceOnce a week a short summary per campaign, with how many contacts opened, clicked and later moved a deal forward, is attached to the campaign record in Salesforce.

What we connect

Together we decide which Salesforce records go to Mailchimp and by which rules, and which fields become segments.
We check which parts of the connection your Mailchimp plan allows before promising any flow from the list above.
In Salesforce an administrator sets up access for the pair as an External Client App, limited to contacts, leads and campaigns.
Where the rules are better kept inside Salesforce, we build them with Flow, so your administrator can change them later without us.
The first sync runs on a small part of the list; after you check it, we move everything else.

Automation scenarios

The monthly export file

Before marketing asks sales for an export, cleans it and uploads it to Mailchimp.

After new and changed Salesforce records reach the right audience on their own, with their segments.

A call to a warm lead

Before the manager calls without knowing the lead read yesterday's email.

After the lead's record shows the click and the campaign, and the call starts from what interested them.

Someone who asked to stop

Before an unsubscribed contact comes back in the next export and gets campaigns again.

After the unsubscribe is marked in Salesforce and the pair does not add that person back.

How it works technically

For those who want to check: each point links to the official documentation page it comes from.

Mailchimp's Marketing API gives programmatic access to account data — enough to sync email activity and campaign analytics with an external system, and to manage audiences and campaigns.
Source: mailchimp.com ↗ checked 2026-09-25
Which parts of the connection are usable depends on the account's Mailchimp plan level.
Source: mailchimp.com ↗ checked 2026-09-25
The Marketing API allows up to 10 simultaneous connections; going over that returns a 429 error.
Source: mailchimp.com ↗ checked 2026-09-25
REST API gives programmatic access to Salesforce records, metadata and search without using the Salesforce interface itself.
Source: developer.salesforce.com ↗ checked 2026-09-25
Access is authorised through OAuth 2.0 via a Connected App or External Client App; since Spring '26, creating new Connected Apps is restricted and Salesforce recommends External Client Apps instead (existing Connected Apps keep working).
Source: developer.salesforce.com ↗ checked 2026-09-25
Salesforce Flow is a no-code automation builder that runs on the same platform as Apex code and can automate steps for any record type.
Source: developer.salesforce.com ↗ checked 2026-09-25

Limits

The limits come from both systems. Which parts of the Mailchimp connection are available depends on the account's plan, so we confirm the flows after checking it. Mailchimp accepts up to 10 simultaneous connections, so a large first sync runs in portions rather than all at once. Email activity comes back as a summary on the record, not as every single open. On the Salesforce side, access for new connections is set up as an External Client App, since creating new Connected Apps is now restricted. A person who unsubscribed is never added back by the pair.

How to start

Three steps from a first message to work on your project.

01
Leave a request
Describe the task in the form — in text or by voice. Budget and timing are optional.
02
We review and estimate
A developer studies the brief, asks about anything unclear and sends an estimate.
03
We start
Once scope and price are agreed, the work begins.

Leave a request

or write to info@coreviaflow.space

Live project We built and run Gemalli — a B2B export platform with producer pages, a CRM and a deal chat. Read the case →

Questions

Will every Salesforce contact end up in Mailchimp?

No, only the records that match the rules we agree with you. Contacts outside those rules stay only in Salesforce.

Does it depend on our Mailchimp plan?

Yes. Mailchimp decides which parts of the connection are usable by plan level, so we check your account first and say plainly which flows it supports.

Can sales see who opened a campaign?

Yes, as activity on the contact or lead in Salesforce, with the campaign name and date.