MarketingCustom integration

HubSpot Mailchimp integration

HubSpot CRM and Mailchimp in sync with no overlap, plus dynamic segmentation.

Request this integration Book a 30-min call

HubSpot

↔

Mailchimp

Implementation time · 4-7 días laborables

Diagnosis

The problem

Many companies run HubSpot Pro but rely on Mailchimp for high sending volume (because HubSpot Marketing Hub Pro gets expensive on contacts). Without a serious integration, the two systems drift apart: contacts created in HubSpot never reach Mailchimp, unsubscribes in Mailchimp never propagate to HubSpot, and lifecycle stages do not segment in Mailchimp. The result: campaigns sent to inactive contacts, GDPR at risk, and marketing operations spending hours every week on CSVs.

Proposal

The solution

HubSpot as the single source of truth CRM, Mailchimp as the engine for transactional and bulk marketing email. Every HubSpot contact is replicated to Mailchimp with its dynamic segmentation (lifecycle stage, lead score, last engagement). Unsubscribes in either system propagate to the other. Clean GDPR compliance: consents traced with timestamp and source.

Scope

What we automate

HubSpot contact to Mailchimp audience with tags by lifecycle stage
Lifecycle stage change to dynamic re-segmentation in Mailchimp
HubSpot lead score above X to VIP tag in Mailchimp
Mailchimp unsubscribe to 'no marketing' flag in HubSpot
Mailchimp hard bounce to invalid email in HubSpot
Mailchimp engagement (open, click) to activity in the HubSpot timeline
GDPR: consents traced with timestamp and source
Multi-audience Mailchimp: by country, language, vertical

Who uses it

Real use cases

These are the profiles that most ask us for the HubSpot ↔ Mailchimp integration and what they get in the end.

Case 01

B2B running HubSpot Pro plus Mailchimp for bulk sends

Before: Mailchimp lists out of date, unsubscribes not propagated.

After: HubSpot as single source. Mailchimp a mirror that stays up to date.

Case 02

Company with complex lifecycle stages

Before: Segmenting Mailchimp by CRM stage was impossible.

After: Each HubSpot lifecycle stage to a dedicated Mailchimp segment. Hyper-personalized campaigns.

Case 03

Company with strict GDPR

Before: Mailchimp unsubscribes never reached HubSpot, a legal risk.

After: Bidirectional unsubscribes with full traceability. GDPR auditable and current.

Before / After

What changes exactly

Without the integration

Mailchimp lists permanently out of date
GDPR unsubscribes not propagated, a legal risk
Manual segmentation with weekly CSVs
Mailchimp engagement invisible to the CRM

✓

With the integration

Mailchimp always in sync with HubSpot
Bidirectional unsubscribes, fully audited
Dynamic segmentation by lifecycle and score
Mailchimp engagement in the HubSpot timeline

Architecture

How we build it

HubSpot webhooks (contact.creation, contact.propertyChange) plus the Mailchimp API and Mailchimp webhooks (subscribe, unsubscribe, profile). Persisted idempotent queue. The mapping logic (HubSpot lifecycle to Mailchimp tag/segment) lives in versioned config. GDPR compliance: every consent propagation is audited.

flow.ts

webhook mailchimp.event

→ queue.enqueue(jobId)

→ worker.handle() // idempotent

→ hubspot.api.call() // retries with backoff

→ log.emit({ status: 'ok' })

FAQ

Frequently asked questions

Why not use HubSpot alone for bulk email?

HubSpot Marketing Hub Pro bills by number of contacts, which gets expensive past 5-10k contacts. Mailchimp is cheaper for bulk sending. This integration lets you keep the best of both.

Does it work with Mailchimp Transactional?

Yes. If you split transactional into Mandrill and keep marketing in standard Mailchimp, we support it. Configurable.

HubSpot Free?

It works with Free, Starter, Pro and Enterprise. Free has API call limits that we account for. Pro and above give access to workflows and custom properties that we make the most of.

What about duplicates across lists?

Matching is done by primary email. If a contact is in 2 Mailchimp audiences, it stays in both but with consistent propagation of unsubscribes and changes.

Does it support Mailchimp predictive segments?

Yes. If your Mailchimp Pro plan has predictive segments, we expose them as HubSpot properties for use in CRM workflows.

How long does it take?

Between 4 and 7 business days. Multi-audience with complex segmentations: 8-10.

We also build

Related integrations

See catalog

Marketing

Shall we talk about your Mailchimp integration?

A 30-minute call, no strings. You leave with scope and a price.

I want this integration See all integrations