What This Integration Does
This integration syncs HubSpot contacts into Constant Contact lists so newsletter sends pull from live, accurate CRM segments — and writes Constant Contact email engagement back to HubSpot so the sales team can see who opened the last newsletter and who clicked through to the offer.
It is the integration for businesses that prefer Constant Contact’s straightforward email experience but run their CRM in HubSpot and want a single source of truth.
The Workflow
The integration listens to HubSpot list memberships. When a contact is added to a HubSpot list configured to sync, they are added to the corresponding Constant Contact list with the agreed fields populated — first name, last name, company, custom industry or segment tags. When a contact is removed from the HubSpot list, they are removed from Constant Contact. New HubSpot contacts not on a synced list are not pushed, so Constant Contact only ever holds contacts the business has actively decided to email.
A specific chain: HubSpot owns a “Newsletter Subscribers” smart list filtered by lifecycle stage, lead status, and subscription preference. A new lead opts in through a HubSpot form. They land in the smart list within seconds. The integration adds them to the Constant Contact “Monthly Newsletter” list and tags them with their industry segment. When the next newsletter sends, Constant Contact emails the live list — including this new subscriber — and the engagement (opens, clicks, hard bounces, unsubscribes) flows back to HubSpot as timeline events on the contact record.
Hard bounces and unsubscribes are handled carefully. A hard bounce in Constant Contact triggers a HubSpot property update marking the email invalid so the sales team stops sending to it. An unsubscribe sets the HubSpot subscription preference to opted out, removing the contact from any future synced lists automatically.
Before and After
Before, the marketing team exports HubSpot contacts each month, uploads them to Constant Contact, and accepts that the list is stale by the time the newsletter sends. Engagement reports live in Constant Contact and never make it back to the sales record. Unsubscribes are reconciled manually, occasionally.
After, Constant Contact lists are always current. Engagement appears in HubSpot on the contact timeline. Unsubscribes update HubSpot the same minute they happen. The marketing manager builds the list once in HubSpot and trusts the sync.
Who Needs This
Small and mid-market businesses that adopted Constant Contact for email simplicity before moving to HubSpot for CRM, or businesses where Constant Contact serves a specific newsletter audience and HubSpot serves sales. The integration becomes worth building once list maintenance becomes a real cost or the marketing team stops trusting their numbers.
How We Build This
We build this against the HubSpot CRM API and the Constant Contact v3 API, using HubSpot workflows or list-membership webhooks as the trigger source and Constant Contact’s contact and engagement endpoints for writes and reads. OAuth refresh is handled automatically and every sync action is logged for audit. See HubSpot API Integration for the HubSpot capabilities involved.
Get HubSpot and Constant Contact Connected
If your HubSpot CRM and your Constant Contact lists are drifting apart and your newsletter sends are based on month-old data, we can connect them with a custom integration that keeps the two in step.