ESP Integrations

When Broadcast sends an email through your provider, the story does not end at delivery. Your ESP continues to track what happens next – whether the message bounced, was opened, got clicked, or triggered a spam complaint. ESP integrations bring all of that data back into Broadcast so you have a complete picture of every email you send.

Why Webhooks Matter

Without webhooks, Broadcast only knows that it handed an email off to your provider. It cannot tell you whether the message actually landed in someone’s inbox, bounced, or was marked as spam. Webhooks close that gap by having your ESP push event data back to Broadcast in real time:

• Delivery confirmation – know definitively when a message reaches the recipient’s mail server
• Bounce detection – identify invalid addresses immediately so you stop sending to them
• Spam complaints – catch complaints early to protect your sender reputation
• Open and click tracking – measure engagement without relying solely on Broadcast’s native tracking
• Automatic suppression – Broadcast deactivates subscribers who bounce or complain, keeping your list clean

Native Tracking vs ESP Tracking

Broadcast offers its own open and click tracking built in. ESP webhook tracking provides a complementary data source. Here is how they compare:

For the most complete picture, use both. Broadcast’s native tracking works immediately with no extra configuration, while ESP webhooks add delivery-level events and serve as a second data source for engagement metrics.

Finding Your Webhook URLs

Every provider integration has a unique webhook URL that you will configure in your ESP’s dashboard. To find yours:

1. Go to Settings > ESP Integrations in your Broadcast dashboard
2. Locate your email provider in the list
3. Copy the webhook URL shown for that provider

Each URL is specific to your account and provider, so make sure you copy the correct one.

Provider-Specific Setup

AWS SES

AWS SES has the deepest integration with Broadcast. When you connect SES via the API delivery method, Broadcast can automatically configure SNS topics and SES event destinations for you.

Full integration features:

• Automatic webhook setup through SES configuration sets
• Suppression list sync – Broadcast can pull your SES account-level suppression list and merge it with your subscriber data
• Events tracked: delivery, bounce, complaint, open, click, reject

If you are using SES via SMTP, you can still set up webhooks manually through the AWS console by creating an SNS topic, subscribing Broadcast’s webhook URL, and configuring a SES event destination to publish to that topic.

Postmark

Postmark integrates tightly with Broadcast through API delivery and supports message streams for separating transactional and broadcast traffic.

Setup steps:

1. In your Postmark server settings, go to Webhooks
2. Add a new webhook using the URL from your Broadcast ESP Integrations page
3. Select the events you want to track: delivery, bounce, spam complaint, open, click
4. Save the webhook

Postmark also supports its own unsubscribe mechanism through message streams. If you are using Postmark’s native unsubscribe links, make sure to configure the webhook so those events sync back to Broadcast.

Mailgun

Setup steps:

1. Log in to your Mailgun dashboard and go to Sending > Webhooks
2. For each event type you want to track, add the webhook URL from your Broadcast ESP Integrations page
3. Copy the Signing Key from Mailgun’s webhook settings and paste it into the corresponding field in Broadcast

Supported events: Delivered, Opened, Clicked, Bounced (permanent and temporary), Complained, Unsubscribed

Broadcast verifies Mailgun webhook signatures using your signing key to ensure incoming events are authentic.

SendGrid

Setup steps:

1. In your SendGrid dashboard, navigate to Settings > Mail Settings > Event Webhook
2. Paste the webhook URL from Broadcast – note that the URL includes your broadcast channel ID for routing
3. Enable Signed Event Webhook Requests for security
4. Copy the Verification Key from SendGrid and enter it in Broadcast’s ESP integration settings
5. Select the events to track and enable the webhook

Supported events: Delivered, Opened, Clicked, Bounced, Spam Report, Unsubscribe, Group Unsubscribe

SendGrid’s signed webhooks provide an extra layer of security. Broadcast validates every incoming request against your verification key and rejects anything that does not match.

Resend

Setup steps:

1. In your Resend dashboard, go to Webhooks
2. Add a new webhook using the URL from Broadcast’s ESP Integrations page
3. Select the events to subscribe to

Supported events: email.sent, email.delivered, email.bounced, email.complained, email.opened, email.clicked

Resend’s webhook payloads include detailed metadata that Broadcast uses to match events back to the specific email and subscriber.

SMTP.com

SMTP.com webhook integration requires coordination with their support team. Contact SMTP.com support and provide them with the webhook URL from your Broadcast ESP Integrations page. Their team will configure the event forwarding on their end.

Inboxroad

Inboxroad uses an API-based sync model rather than traditional webhooks. Broadcast periodically pulls event data from the Inboxroad API.

In your ESP Integrations settings for Inboxroad, you will see a Sync Now button that triggers an immediate data pull. This is useful when you want to verify the integration is working or need up-to-date event data right away. Broadcast also runs automatic syncs on a regular schedule.

Auto-Suppression Behavior

One of the most important functions of ESP integrations is automatic subscriber suppression. When Broadcast receives certain events from your provider, it takes protective action:

• Hard bounces – the subscriber is deactivated immediately and their email is added to your global suppression list. No further emails will be sent to this address across any of your channels.
• Spam complaints – same treatment as hard bounces. The subscriber is deactivated and suppressed globally.
• Soft bounces – Broadcast tracks these but does not immediately suppress. Repeated soft bounces over time may lead to deactivation depending on your provider’s policies.

This automatic suppression protects your sender reputation by ensuring you never repeatedly send to addresses that are bouncing or generating complaints. The global suppression list works across all your broadcast channels, so a problematic address is blocked everywhere.

Troubleshooting

Webhooks Not Being Received

• Verify the URL – double-check that you copied the exact webhook URL from Broadcast’s ESP Integrations page. A missing character or extra slash will cause failures.
• Check your provider’s webhook logs – most ESPs show delivery attempts and response codes for webhook calls. Look for 4xx or 5xx errors.
• Confirm the webhook is enabled – some providers require you to explicitly activate webhooks after creating them.

Events Not Appearing in Broadcast

• Allow processing time – webhook events are processed through a background job queue. During high-volume sends, there may be a short delay.
• Check event selection – make sure you enabled the specific event types you want in your provider’s webhook settings.
• Verify the email server match – Broadcast matches incoming webhook events to the email server that sent the original message. If the server configuration changed, events may not link correctly.

Authentication Errors

• Signing key mismatch – for providers like Mailgun and SendGrid that use signed webhooks, verify that the signing or verification key in Broadcast exactly matches the one in your provider’s dashboard.
• Key rotation – if you rotated your webhook signing key in your provider’s settings, update it in Broadcast as well.

Next: Domain Names – Configure custom domains for your email links, tracking, and opt-in forms.