Partner spotlight: Master Inbox
Master Inbox is a unified inbox that combines social and email conversations for sales teams. See how it connects to OutboundSync in beta.
Jason Ma
Masterinbox → Attio
Masterinbox + Attio integration
Bring the conversations from every Master Inbox account into Attio. OutboundSync writes a Note on the Person for each event and can store it as a structured record.
BetaOne-way syncEmail and social
Masterinbox + Attio at a glance
Master Inbox connects to Attio through OutboundSync. Outgoing and incoming messages from the email and social inboxes connected to Master Inbox, plus label changes and prospect list changes, each write a Note on the matched Attio Person. The optional OutboundSync custom object stores every event as a record you can filter.
| Status | Beta (Attio is a one-way beta CRM) |
|---|---|
| Channels | Email and social |
| Direction | One-way, Masterinbox → Attio |
| Attio records | People, with the related Company |
| Block lists | Not available for this pairing |
| Masterinbox plan | Needs webhook access |
| Setup | Guided: the OutboundSync team runs onboarding |
Master Inbox gathers conversations from many accounts, and Attio is good at organizing them once they arrive. The OutboundSync object stores each message and label change with its platform, event type, and message text, which lets you build Attio views across every inbox without caring which sender handled the thread.
Label changes are the most useful filter. An Attio list of People whose Master Inbox label moved to interested gives the team one clean follow-up queue, while the Note on each Person keeps the readable conversation.
What syncs from Masterinbox to Attio
Every event below arrives in near-real time and lands on the matched Attio record. Pick the ones you want per source.
| Event | Channel | Where it lands in Attio |
|---|---|---|
| Message sent— Outgoing messages from connected accounts, logged as email sends | Note on the Person, plus an optional OutboundSync record | |
| Email received— Incoming messages on connected email accounts | Note on the Person, plus an optional OutboundSync record | |
| Social message received— Incoming messages on connected social accounts | Social | Note on the Person, plus an optional OutboundSync record |
| Label changed | Note on the Person, plus an optional OutboundSync record | |
| Prospect list changed | Note on the Person, plus an optional OutboundSync record |
Event names come from the Masterinbox webhooks OutboundSync receives. Attio is a one-way beta, so exact event coverage is confirmed during onboarding. See the Masterinbox event reference.
What teams do with Masterinbox + Attio
Filter by label
List People whose Master Inbox label changed to interested for follow-up.
Search conversations
Message text on OutboundSync records makes past replies easy to find.
Unify senders
Conversations from every Master Inbox account land on one Person.
Ways to connect Masterinbox and Attio
The options teams weigh before they commit a production sync.
| Option | What it does | Trade-off |
|---|---|---|
| Zapier, Make, or n8nCompare integration platforms | Catch Masterinbox webhooks and write each event to Attio with a workflow you build. | Every event type, retry, and field change is a workflow you maintain, billed per task or step. |
| Custom buildBuild vs buy | Write your own service against the Masterinbox and Attio APIs. | You own matching, deduplication, API limits, and every upstream schema change. |
| OutboundSync | Pre-built email and social activity sync into Attio People. | One-way beta with guided onboarding. Lighter configuration than HubSpot or Salesforce today. |
How to set up Masterinbox + Attio
Step 1: Connect Attio
Install OutboundSync from the Attio App Store, then optionally create the OutboundSync custom object in CRM Settings.
Step 2: Connect Masterinbox
The OutboundSync team creates your Masterinbox source with you and points Masterinbox's webhooks at it.
Step 3: Create the Attio source
Select Masterinbox when you create the Attio source, and confirm how contacts are matched.
Step 4: Send a test event
Trigger one Masterinbox event and confirm it on a real Attio Person.
Step 5: Go live
Launch with the OutboundSync team watching the first production events in Attio.
Plan requirements
Masterinbox plan
Needs webhook access
OutboundSync receives Masterinbox activity through webhooks. Confirm your Masterinbox plan includes webhook access, or ask us to check during setup.
Attio
Attio is a one-way beta. There is no Attio plan gate on our side; onboarding runs with the OutboundSync team.
Related integrations and guides
Masterinbox with other CRMs
Other outbound tools for Attio
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TapcheckMasterinbox + Attio FAQ
What Masterinbox activity does OutboundSync sync to Attio?
Message sent, email received, social message received, label changed, and prospect list changed.Which Attio records does it write to?
OutboundSync matches or creates Attio People. Masterinbox events land as note on the Person, plus an optional OutboundSync record. See the Attio beta guide for details.Do Master Inbox messages attach to Attio Companies?
They attach to the Person. The related Company is matched or created too, and its ID is stored on the optional OutboundSync record for filtering.Is the integration one-way or two-way?
One-way. Activity flows from Masterinbox into Attio, and nothing is written back to Masterinbox.Can I use Attio records as a block list?
Not today. Block lists come from HubSpot lists or Salesforce reports. The Attio beta syncs activity in only.Do I need admin access to set it up?
An Attio workspace admin installs OutboundSync from the Attio App Store during guided onboarding.Which Masterinbox plan do I need?
OutboundSync receives Masterinbox activity through webhooks. Confirm your Masterinbox plan includes webhook access, or ask us to check during setup.How is Masterinbox + Attio priced?
Beta access is scoped with the OutboundSync team during onboarding. Billing follows the same model as every plan: sent messages per month. Replies, opens, clicks, and lead-category updates are not billed. See the pricing page.Can I do this with Zapier, Make, or n8n?
Yes, for lightweight automation. Zapier, Make, and n8n are good for prototypes and simple routing, but they need ongoing maintenance and bill by task or step. OutboundSync is pre-built for outbound CRM sync, keeps searchable event logs beyond 30 days, and prices by outbound volume.What breaks first when this scales?
Data quality and reliability break first: duplicate events, retries, out-of-order webhooks, and bursts during big sends. OutboundSync handles idempotency, timing buffers, and queue recovery, and flags suspicious or mismapped payloads instead of writing them.
Masterinbox resources
Tutorials, case studies, and updates related to Masterinbox.
See Masterinbox activity in Attio
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