Reply to cold email leads from the HubSpot contact record

When a lead turns Interested, Master Inbox syncs the contact to HubSpot. Reps then read the whole email or LinkedIn thread and reply from the Master Inbox card on the HubSpot record, through the original mailbox.

CRM sync

HubSpot

HeyReach

SmartleadRepFounderRevenue plan

When

Add LabelInterested

Then

Sync to HubSpotUpsert the contact; the Master Inbox app card on the record shows the thread and a reply box

Why teams run it

Reps who live in HubSpot answer cold replies without switching tabs or sending from the wrong address.

Set it up in Master Inbox

In Master Inbox, open Settings, then Workflows, and click Add a workflow.
Name it Reply to cold email leads from the HubSpot contact record.
Set the trigger to Add Label and choose Interested.
Add the action Sync to HubSpot: Upsert the contact; the Master Inbox app card on the record shows the thread and a reply box.
Save the workflow and switch it to Active.

Before you start, connect HubSpot under Settings, Integrations.

Or create it with the API

Everything in the workflow builder is also in the Master Inbox API. This request creates the same workflow. Replace the example ids with your own label, list and campaign ids from GET /workflows/filter-fields.

curl -X POST https://api.masterinbox.com/api/api-webhook/v1/api/workflows/create-workflow \
  -H "Authorization: Bearer $MASTER_INBOX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "name": "Reply to cold email leads from the HubSpot contact record",
  "trigger_type": "add_label",
  "trigger_config": {
    "label_ids": [
      176479
    ]
  },
  "action_configs": [
    {
      "action_type": "sync_to_hubspot"
    }
  ]
}'

Full reference: workflow API guide and API docs.

Or ask Claude, ChatGPT or Grok to build it

Our workflow guide is written for AI agents to read. Give your assistant your API key and this prompt:

Read https://app.masterinbox.com/public-workflow-api.md and use my Master Inbox API key to create this workflow: "Reply to cold email leads from the HubSpot contact record". First call GET /workflows/filter-fields and look up my label, list and channel ids, then create the workflow and tell me what you set up.

Questions

Does the reply go out from the cold mailbox?

Yes. Replies from the HubSpot card send through the original outreach channel and sync back to the thread.

Which channels can reps answer from HubSpot?

Email and LinkedIn threads, including HeyReach, Smartlead and lemlist conversations.

Can I build this workflow through the API?

Yes. Send the create-workflow request shown on this page with your Master Inbox API key. The API checks the payload first and lists every problem by field if anything is off.

Which plan includes this?

This workflow works on the Revenue plan. Every plan has unlimited users and starts with a free 7-day POC.