AI Email – HubSpot Integration Details and Requirements

  • Updated on Jul 21, 2025
  • Published on Jun 27, 2025
  • 9 minute(s) read
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AI Email (AIE) integrates with HubSpot.

6sense non-tech-fit CRM customers (those not using Salesforce, Dynamics, or HubSpot CRM) who are standalone AI Email customers and use the HubSpot platform as a MAP can connect their HubSpot instance as a CRM integration to use the AI Email product.

HubSpot implementation requirements

This integration requires a HubSpot Administrator with: Super Admin Access.

  • You can either create a 6sense-HubSpot ‘Super Admin’ user OR choose an existing ‘Super Admin’ user in HubSpot.

  • With ‘Super Admin’ permission granted to the new or existing user, 6sense will get Read/Write access to all of your HubSpot objects.

Integration process

To setup your HubSpot CRM integration in 6sense:

  1. Go to Settings > Integrations.

  2. Select HubSpot.

  3. Select Connect and then Sign in with HubSpot credentials.

  4. Select Next.

  5. Enter Rest API limits and select Save & Next.

  6. Toggle the Data sync flag to ON.

  7. Select Finish.

The following API limits apply to the HubSpot CRM integration according to the HubSpot API Usage Guidelines:

Product Tier

Limits

Free & Starter

  • Burst: 100/10 seconds

  • Daily: 250,000

Professional & Enterprise

  • Burst: 150/10 seconds

  • Daily: 500,000

API add-on (any tier)

  • Burst: 200/10 seconds

  • Daily: 1,000,000

Refer to the Real-time syncs section below to enable real-time syncs for AIE.

What happens if I don’t turn the “Data Sync” flag to the ON state (6th step)?

6sense will start syncing your HubSpot account data only if the “Data Sync” flag is ON. If Data Sync flag is OFF, then 6sense will not sync your HubSpot account.

HubSpot real-time sync

Real-time syncs query the source CRM at an expedited cadence – every 5 minutes by default – to identify updates and push them to 6sense capabilities for activation.

Real time syncs are enabled via the Integrations Settings page. Navigate to Settings > Integrations > Salesforce/HubSpot CRM.

Enable real-time sync for HubSpot

  1. For customers who integrated HubSpot CRM before May 17th 2024, you need to authenticate the HubSpot login in the Integration UI by clicking on the Sign in button again or follow the 3rd step from the HubSpot CRM integration article.

  2. Existing integration and package:

  3. Roles and permissions:

    • Primary 6sense Administrator, or

    • AIE Administrator

Enable real-time syncs

  1. Navigate to the Real Time Data Sync in Integrations Settings by selecting the relevant integration.

  2. Update API Limits. This increase in API calls allows 6sense to query your CRM instance every 5 minutes to check for updates. We recommend you to increase each type of API limit by the following amounts depending on the Integration:

    CRM

    REST API

    BATCH API

    SOAP API

    Hubspot

    10,000

    NA

    NA

  3. Select Save & Next.

  4. Select Finish to complete the set up of the new API limits.

  5. Select the toggle to enable real-time data syncs. Once you’re ready, change the Data Sync toggle to ON and 6sense will start the process to activate real-time syncs for your instance.

    It can take up to 24 hours to sync your historical CRM data so that 6sense can process record updates. Keep in mind that once you turn it on, you will have to reach out to the 6sense Support Team to turn it off.

What happens if API Limits are reached during real time syncs?

If the API limits are reached:

  1. 6sense will stop syncing data from the source system until the next day.

  2. 6sense will send a notification indicating the API limits for the source system have been reached and prompt the admin to consider increasing the API limits.

Impacts to 6sense processes when API limits are reached:

  • If the API limits are reached during real-time syncs:

    • Syncs will be paused for the remainder of the day.

    • Exports from 6sense to the source system will be paused for the remainder of the day.

    • Enrollments will be paused for the remainder of the day. AIE will be unable to write back AIE status to HubSpot when API limits are reached.

As you can see, it is imperative to ensure the API limits are high enough to accommodate 6sense API usage.

API calls to HubSpot

The AI Email - HubSpot integration uses contact lists to assign contacts to a campaign. AIE will check from what real-time sync has already pulled. The bulk of the API calls that AIE will use is whenever there are activities surrounding a contact such as sending/receiving an email from them.

API calls

  • Each time a contact is enrolled, an API call is triggered to update their sixsense_ce properties

  • Each time AIE sends an email to the contact, an API call is triggered to record this email.

  • Each time a contact replies, an API call is triggered to record this email.

  • Each time a contact changes status in AIE (such as Qualified, Not Interested, etc.), an API call is triggered to update their sixsense_ce properties.

Example of API calls

  • 2 Hubspot integrated campaigns

  • 500 contacts in each campaign

  • 5 emails in Main Sequence

2 x 500 = 1,000 API requests to enroll the contacts

2 x 500 x 5 = 5,000 API requests to create email records for the sent emails in the main sequence

2 x 500 = 1,000 API requests to update the status of the contact at the conclusion of the conversation

Total: Approx. 7,000 API requests per month. (This is for AIE alone. Real-time sync has its own set of API calls that are outside the scope of this document.)

Is there a way to limit the API calls if we are concerned about the number of API calls this will utilize?

Yes.

Minimum object requirements for CRM integrations for AIE-only customers

This chart contains all the mandatory objects required from the customer’s HubSpot CRM that must be synced with the 6sense platform during onboarding. We require read permissions for all the listed objects:

External Object Name

6sense Object Name (Backend)

6sense Object Display Name

Purpose

Contacts

contacts

Hubspot CRM Contacts

Mandatory object for all the packages. Need this data for campaigns enrollment for sending the campaigns

Companies

companies

Hubspot CRM Companies

Mandatory object for all the packages

Owners

owners

Hubspot Owners

For matching the sales rep’s email to an owner email and for assigning the contact

Contacts->Lists

crm_contact_list

Hubspot Contact List

Contact list is used to fetch the contact lists where the AIE campaigns should be triggered

Contacts->Lists members

crm_contact_list_members

HubSpot Contact list members

Used in retrieving the contacts and for enrolling them to the campaigns

Edit permissions are required in order to push updates to the six HubSpot properties, Do Not Contact property, and record email activities.

Mapping contact fields

AIE will pre-map these 5 contact fields below by default because they are required by our system to create an AIE contact record.

  • Id

  • First Name

  • Email

  • Account – Name (for HubSpot Company)

  • Account – Id (for HubSpot Company)

You can go on to map any number of contact fields in HubSpot to other pre-populated and custom AIE contact fields in the Field Mappings table.

We recommend that you map these 4 fields below so that you can personalize your emails (with merge tags) using the field values:

  • Last Name

  • Company name

  • Job Title

  • Contact Owner Email

The process for mapping your HubSpot company fields to AIE account fields is very similar to the above process for mapping your lead fields.

AIE will pre-map these 2 account fields by default:

  • Id

  • Name

By pre-mapping the company ID, our system will allow you to associate a Hubspot-enrolled contact in AIE with their respective HubSpot company.

You can go on to map other HubSpot company fields to pre-populated and custom AIE account fields. This is a necessary step for further personalizing your email messaging in AIE using the account field values as merge tags.

Difference between default fields and custom fields

Default field mapping

AIE’s integration with HubSpot maps some fields automatically. These default field mappings for contacts include but are not limited to:

  • Id (HubSpot) -> CRM Object Id (AIE)

  • First Name (HubSpot) -> First Name (AIE)

  • Email (HubSpot) -> Email (AIE)

At this moment, you will not be able to change the mapping of the default fields.

Custom field mapping

Other than the three fields above, you will be able to add, remove and map more fields from HubSpot to AIE. This will help you to have more options to personalize the emails and collect more data for your CRM from AIE.

HubSpot properties details

As part of your AIE implementation, you enable the real-time sync flag in the Integration UI. The following data is synced back to HubSpot in the contact Information properties. It will take 5-10 minutes for the creation of these properties after enabling real-time sync in the integration UI.

  • Campaign name (sixsense_ce_campaign_name)

  • Campaign status (sixsense_ce_campaign_status)

  • Campaign creator (sixsense_ce_campaign_creator)

  • Campaign URL (sixsense_ce_campaign_url)

  • Contact email conversations and status (sixsense_ce_status)

  • Contact last synced date (sixsense_ce_last_synced_at)

Sync AIE data to HubSpot

The following data is synced back to HubSpot in the Contact Information properties.

  • Campaign/Status Info

  • Campaign name (sixsense_ce_campaign_name)

  • Campaign status (sixsense_ce_campaign_status)

  • Campaign creator (sixsense_ce_campaign_creator)

  • Campaign URL (sixsense_ce_campaign_url)

  • Contact email conversations and status (sixsense_ce_status)

  • Contact last synced date (sixsense_ce_last_synced_at)

  • Contact Email Conversations (via “Activity” tab or “Emails” tab)

  • Do Not Contact

HubSpot storage considerations

The bulk of storage usage will come from recording the email activities. The fields added to the contact objects are small (single-line string).

In order to get an estimate of the amount of storage AIE will use, we suggest using the baseline of app x 1KB per email. (Note: We do not include attachments in the sent/received email activities, so these do not require any additional storage.)

Example of storage estimation

3000 contacts are enrolled into a campaign with 4 emails in the main sequence.

3000 x 4 x 1KB = 12MB of storage in HubSpot for the email activities.

In the contact record’s lifetime in AIE, we typically send less than 10 emails per campaign if the contact never replies, so it is highly unlikely to reach HubSpot’s limit of 10000 Contact_To_Email association.

Is it possible to turn off the sync of emails back to HubSpot if there is concern about storage space?

Yes – it is possible. However please note that this would also disable the writeback of status updates (qualified, not_interested, etc.) as these data points are bundled together. Other fields – such as campaign, DNC, etc. – are not bundled and could still be written back.

If the sync of email activities is disabled, the amount of storage used is minimal.

HubSpot contact enrollment requirements

You can auto-enroll or enroll leads directly from HubSpot contact lists into AIE. If auto import is enabled, leads meeting your specified rules will be automatically imported into AIE.

Contact list is the only list type supported.

FAQ

What HubSpot API does AIE use?

AIE uses the REST API.

Is there a way to limit the API calls if we are concerned about the number of API calls this will utilize?

Yes. Go to Setting > Integrations > HubSpot > Manage.

Is it possible to turn off the sync of emails back to HubSpot if we are concerned about storage space?

Yes – it is possible. However please note that this would also disable the writeback of status updates (qualified, not_interested, etc.) as these data points are bundled together. Other fields – such as campaign, DNC, etc. – are not bundled and could still be written back.

How often does the sync run? What is the frequency of updates?

Real-time syncs query the source CRM at an expedited cadence – every five minutes by default – to identify updates and push them to 6sense capabilities for activation.

What Properties does the integration create in HubSpot?

All the components are listed in this link and above in this documentation. There are six fields to be added to Contact Information Properties.

What contacts will be synced with the integration?

The AI Email - HubSpot integration uses the contact list to determine which contacts to enroll in an AIE campaign.

What fields need write access?

All of the properties listed under HubSpot Properties Details.

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