Master Inbox
Integrations and Webhooks

SmartLead Integration

In this guide, you'll learn how to connect Smartlead to Master Inbox, including API setup, DNC configuration, Exclusive Tags, label syncing, and prospect options, so your campaigns and replies stay fully in sync.

Steps to Connect Smartlead

Step 1 — Open the Smartlead Integration

In MasterInbox, navigate to Integrations and click on SmartLead

SmartLead integration screen

Step 2 — Add Your API Key

  1. Log in to your SmartLead account

  2. Go to Settings → API Key

  3. Copy your API Key

  4. Paste it into MasterInbox

Paste API key in MasterInbox

Optional - Replace the SmartLead logo with a different logo

MasterInbox allows you to replace the default SmartLead logo with a custom logo.

This is useful for agencies managing multiple clients or teams that want a more branded workspace experience.

Step 3 — Select a Client Account

Choose the client account you want to connect with MasterInbox

Select client account

Step 4 — Configure DNC Settings

Select the DNC (Do Not Contact) lists you want to apply

What is DNC and how it works:

This setting makes sure that anyone marked as Do Not Contact is never emailed again.

If a prospect is added to a DNC list in SmartLead or MasterInbox, MasterInbox will automatically stop messages from being sent to them.

Why this is important for agencies:

  • Prevents accidentally emailing opted-out prospects

  • Protects your sender reputation

  • Keeps you compliant with client rules and regulations

  • Avoids awkward or risky follow-ups

Example:

If a prospect replies “Please don’t contact me again” and is added to a DNC list in SmartLead, MasterInbox will recognize this and make sure no future campaigns or replies reach them

Configure DNC settings

Step 5 - Set Exclusive Tags

Exclusive Tags let you control exactly which contacts are synced between SmartLead and MasterInbox.

When this is enabled, only prospects with the selected tags will sync.

Everyone else is ignored.

Think of it as a filter at the door.

Why this is useful for agencies:

  • Prevents clutter from syncing every lead

  • Keeps inboxes clean and focused

  • Helps manage multiple clients and campaigns safely

  • Avoids mixing test leads, warmups, or internal contacts with real prospects

Example use cases:

Agency with multiple clients

  • Tag prospects as Client A, Client B

  • Enable Exclusive Tags

  • Select only Client A

    👉 Only Client A’s prospects sync into MasterInbox

SDR / BDR team

  • Tag prospects as Hot, Warm, Cold

  • Enable Exclusive Tags

  • Sync only Hot

    👉 Team focuses only on high-intent replies

Campaign-specific syncing

  • Tag prospects as Webinar, Cold Email, LinkedIn

  • Enable Exclusive Tags

    👉 MasterInbox only shows replies from the campaign you care about

Best practice:

  • Use clear, consistent tags

  • Avoid syncing everything by default

  • Turn this ON when handling multiple campaigns or clients

Step 6 — Sync Labels

You have two toggles here:

  • SmartLead → MasterInbox: Syncs labels from SmartLead into MasterInbox

  • MasterInbox → SmartLead: Syncs labels created or updated in MasterInbox back into SmartLead

Important — only enable one at a time.

Which one you enable depends on where your labeling happens:

  • If you're using AI labeling on MasterInbox → enable MasterInbox → SmartLead

  • If you're doing your labeling inside SmartLead → enable SmartLead → MasterInbox

Step 8 — Configure Prospect Sync Options

  • Enrich Prospect: When toggled ON, MasterInbox will automatically fetch additional information about your prospects from SmartLead. This includes any custom fields you've added in SmartLead, all of this data will appear in the side panel inside MasterInbox.

  • Campaign Data: When toggled ON, the campaign name will sync from SmartLead into MasterInbox.

    If you work with overlapping leads across multiple clients, it's recommended to keep Campaign Data turned OFF. This helps avoid confusion when the same prospect appears in different client campaigns.

Enabling these ensures that all relevant prospect and campaign insights are always up-to-date in both tools.

Step 9 - Submit to Integrate

Once all toggles and settings are configured, click Submit to complete the integration.

Your Smartlead account is now connected. Replies from your Smartlead campaigns will start syncing into Master Inbox automatically, with your DNC rules, exclusion tags, label logic, and prospect settings all applied from the start.

Webhook Setup

MasterInbox uses Smartlead webhooks to receive real-time updates for replies, sent emails, and lead status changes.

Configure the Webhook in MasterInbox

  1. Open Settings → Integrations → Smartlead.

  2. Navigate to the Webhook Setup section.

  3. Copy the Webhook URL generated by MasterInbox.

The integration also displays the required Smartlead webhook configuration for reference.

Configure the Webhook in Smartlead

  1. Log in to your Smartlead account.

  2. Navigate to Webhooks.

  3. Click Add Webhook.

  4. Enter a webhook name (for example, MasterInbox Webhook).

  5. Paste the Webhook URL copied from MasterInbox.

  6. Set the Association Type to Account Level.

  7. Select the following Event Types:

    • Email Reply

    • Email Sent

    • Manual Reply Sent

    • Lead Category Updated

  8. Click Update or Save Webhook.

Note: Configure the webhook at the Account Level to ensure events from all applicable campaigns are sent to MasterInbox.

Final Result

Once the webhook is configured:

  • New email replies are synchronized with MasterInbox.

  • Sent emails are tracked automatically.

  • Manual replies are synchronized.

  • Lead category updates are reflected in MasterInbox.

  • Conversation activity stays synchronized in near real time between Smartlead and MasterInbox.

Connect Smartlead Using OAuth

OAuth allows you to securely connect your Smartlead account without manually copying your API key.

Once connected, MasterInbox automatically syncs your selected Smartlead client and its mailboxes.

Step 1 — Connect Your Smartlead Account

On the Smartlead integration page in MasterInbox, click Connect with Smartlead (OAuth).

Step 2 — Sign In

Enter your Smartlead:

  • Email address

  • Password

Click Next to continue.

Step 3 — Select a Smartlead Client

Choose the Smartlead client account you want to connect.

MasterInbox will automatically sync all mailboxes associated with the selected client.

Unlike the API Key connection, individual mailboxes do not need to be connected manually.

Step 4 — Configure DNC Settings

Select the label that should be treated as your Do Not Contact (DNC) label.

You can also configure:

Assign DNC Label to Lead

When enabled, MasterInbox automatically assigns the selected DNC label to matching leads.

Add Domain to Blacklist

When enabled, the prospect's domain is automatically added to your blacklist, preventing future outreach to contacts from that domain.

Step 5 — Configure Tags

Enable Exclusion Tags if you only want specific tagged prospects to sync.

After enabling the toggle, select the Smartlead tags you want to include.

This allows you to control exactly which prospects are synced into MasterInbox.

Step 6 — Configure Label Sync

Choose how labels should sync between Smartlead and MasterInbox.

Available options:

  • Smartlead → MasterInbox

  • MasterInbox → Smartlead

You can also select which labels should be synchronized.

Step 7 — Configure Prospect Sync

Choose which additional prospect data should sync into MasterInbox.

Available options:

Enrich Prospect

Automatically sync additional prospect information, including Smartlead custom fields.

Campaign Data

Sync campaign information so the campaign name is available inside MasterInbox.

Step 8 — Complete the Connection

Click Submit to save your settings.

Your selected SmartLead client, mailboxes, labels, tags, and prospect settings will now begin syncing with MasterInbox automatically.

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