> ## Documentation Index
> Fetch the complete documentation index at: https://partner-integrations.voyado.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sync of email marketing preferences

Email marketing preferences can be synchronized in two different ways between Engage and Shopify, depending on how the integration is configured:

**Webhook disabled**: Preferences are only synced via order events

**Webhook enabled**: Preferences synced continuously based on updates in both systems

In the sections below you'll see how each configuration affects data behavior.

## 1: When webhook is disabled

<Frame caption="Syncing with webhook disabled">
  <img src="https://mintcdn.com/voyado-partners/ukR8WXfaIURY8-RL/images/shopify/shopify-preferences-sync-01.png?fit=max&auto=format&n=ukR8WXfaIURY8-RL&q=85&s=815dba5c24caa2300014513be4e4c356" alt="Syncing with webhook disabled" width="1275" height="272" data-path="images/shopify/shopify-preferences-sync-01.png" />
</Frame>

If the marketing preference webhook in Engage is **not enabled** in the app configuration, email marketing preferences are only synced when the **order/create payload** comes from Shopify, such as when an order is placed. No real-time sync occurs outside of order events.

There are three cases to consider here:

<AccordionGroup>
  <Accordion title="A) Contact does not already exist in Engage">
    When:

    * A customer does not exist in Engage
    * And they place an order in Shopify

    Then:

    * A contact will be automatically created in Engage
    * The `acceptsEmail` value will be set to the marketing preference value in the Shopify order
  </Accordion>

  <Accordion title="B) Contact exists in Engage with acceptsEmail = false">
    When:

    * A customer with marketing preference of "true" places an order in Shopify
    * And they already exists in Engage with `acceptsEmail` = "false"

    Then:

    * The `acceptsEmail` value will be updated to "true" in Engage
  </Accordion>

  <Accordion title="C) Contact exists in Engage with acceptsEmail = true">
    When:

    * A customer with marketing preference of "false" places an order in Shopify
    * And they already exists in Engage with `acceptsEmail` = "true"

    Then:

    * The `acceptsEmail` field is omitted in the update payload
    * The value in Engage remains "true" (meaning that no downgrade occurs)
  </Accordion>
</AccordionGroup>

<Warning>
  So when the webhook is disabled, we will **not** automatically overwrite a positive opt-in with a negative value coming from an order.
</Warning>

## 2: When webhook is enabled

<Frame caption="Syncing with webhook enabled">
  <img src="https://mintcdn.com/voyado-partners/ukR8WXfaIURY8-RL/images/shopify/shopify-preferences-sync-02.png?fit=max&auto=format&n=ukR8WXfaIURY8-RL&q=85&s=8adb0736ca9913409f5b15bd724f18aa" alt="Syncing with webhook enabled" width="1316" height="472" data-path="images/shopify/shopify-preferences-sync-02.png" />
</Frame>

If the Engage marketing preference webhook is enabled:

* We listen to all email marketing preference updates
* Changes are synchronized more dynamically between systems
* Preference updates can override existing values depending on the event type

<AccordionGroup>
  <Accordion title="A) Contact already in Engage when Shopify account is created">
    When:

    * The customer creates a new Shopify account with email marketing preference set to "false"
    * A contact already exists in Engage, having been created via another system, with `acceptsEmail` = "true"

    Then:

    * We omit the `acceptsEmail` field when updating the contact in Engage
    * This means the `acceptsEmail` value will remain "true"

    So we do not automatically downgrade `acceptsEmail` during contact creation when marketing preference is "false".
  </Accordion>

  <Accordion title="B) Contact exists in both systems with different preferences">
    When:

    * In Shopify the marketing preference is "false"
    * In Engage the `acceptsEmail` value is "true"
    * The customer updates billing information in Shopify

    Then:

    * The update payload from Shopify will includes the marketing preference value ("false")
    * This will override the value in Engage so that `acceptsEmail` will now be "false"

    <Warning>
      Because of this behavior, it is critical during onboarding to ensure that email marketing preferences are fully aligned between Shopify and Engage before going live.
    </Warning>
  </Accordion>
</AccordionGroup>

<Tip>
  So when the webhook is enabled:

  * We listen to all email marketing preference updates
  * Changes made in Shopify will update Engage
  * Changes made in Engage can be synchronized back to Shopify (if configured)
</Tip>

## Important exception

We always override an `acceptsEmail` value of "true" in Engage *except* when we receive the **customer create webhook** from Shopify with an email marketing preference value of "false" in the payload.

In other words, a marketing preference value of "false" at customer creation will not downgrade an existing "true" value of `acceptsEmail` in Engage.

## Pre-selected opt-in setting

Voyado does **not** recommend enabling support for **pre-selected opt-in** in the Shopify app setup (or relying on Shopify's pre-selected opt-in behavior).

<Frame caption="Pre-selected opt-in setting">
  <img src="https://mintcdn.com/voyado-partners/ukR8WXfaIURY8-RL/images/shopify/shopify-preferences-sync-03.png?fit=max&auto=format&n=ukR8WXfaIURY8-RL&q=85&s=935651f26e13d0722b628d93b5877fd5" alt="Pre-selected opt-in setting" width="1311" height="268" data-path="images/shopify/shopify-preferences-sync-03.png" />
</Frame>

The reason is that in Shopify, once a customer has opted in, they may effectively remain opted in even if they actively deselect the checkbox in a later checkout. This can lead to inconsistent consent states across systems.

For example, a customer can be unsubscribed in Engage based on an order event, but later be set back to opted-in when Shopify sends a customer update (e.g., after billing details are updated).

Shopify's region-based pre-selection adds further complexity and increases the risk of incorrect consent handling.

<Warning>
  So do not enable the setting above and be sure to align the consent states between Shopify and Engage before go-live.
</Warning>

## Key recommendations

During onboarding, it is essential to:

* Audit and align all email marketing preferences between systems
* Decide whether the webhook should be enabled based on the desired source of truth
* Clearly define whether Shopify or Engage should control opt-in logic going forward

Misalignment before go-live can result in unintended opt-in overrides.