Company-Level CRM Audience Sync Integration (HubSpot & Mailchimp)

The CRM Audience Sync integration keeps your contacts synchronized between your CRM and Letterhead — no manual imports.

Overview

• Available CRMs: HubSpot and Mailchimp.
• Bi-directional sync: changes to First Name, Last Name, and Email are reflected in both systems.
• Channel mapping: map CRM audiences or subscription types to Letterhead channels for automatic syncing. (A channel is where you create and manage an individual newsletter.)
• Always up to date: webhooks keep everything synced instantly.

Roles and prerequisites

• Setting up or deleting a CRM integration is an admin task, since it applies across the whole company. If you don’t see the option, ask an organization administrator.
• API key — create a new company API key in Letterhead. See Generate & manage API keys.
• Server prefix — your Letterhead server prefix (e.g. abc.app.tryletterhead.com) is required during setup.
• Company account — CRM integrations are only available on company-level accounts; your CSM can confirm whether yours qualifies.

HubSpot setup

1. Generate an API key — in Company Settings → API Keys, click Generate New Key and copy it.
2. Configure the integration — open Integrations, select HubSpot, connect your CRM account, then enter your Server Prefix and the API Key you generated.
3. Map subscription types — map CRM subscription types to Letterhead channels. Subscription types come over as Subscribed, Unsubscribed, or Not Subscribed statuses, and one-to-many mapping is supported (multiple subscription types can map to one channel).
4. Review mapped fields and finish — confirm the synced fields (First Name, Last Name, Email), then save.
5. Verify the sync — check the mapped Letterhead channel and your CRM contacts, and confirm records match in both systems.

Mailchimp setup

1. Generate an API key — in Company Settings → API Keys, click Generate New Key and copy it.
2. Configure the integration — open Integrations, select Mailchimp, connect your account, enter your Server Prefix and API Key, then click Next.
3. Fill out the mapping details — choose the channels to sync (or use the All Channels toggle), select the Mailchimp list to sync with, review your selections, and click Finish.
4. Once configured, a green check mark on the integration card shows the integration is enabled.

Managing the integration

• Pause or delete: in Integrations, select the CRM integration, choose More Options → Deactivate Integration, and confirm by entering the text prompt.
• Reconnection: if you disconnect, previously synced data remains, but syncing stops until you reconnect.

Behavior and edge cases

• Only one CRM integration (HubSpot or Mailchimp) can run at a time — deactivate one before enabling the other.
• Webhooks import and update contacts instantly, in both directions: CRM changes sync to Letterhead, and Letterhead changes sync back to the CRM.
• Limited fields: only First Name, Last Name, and Email are synced.

Need help?

See Working in Integrations for everything the Integrations area covers, or contact support.