Definition
A webhook is an HTTP request sent by an email platform to a URL you specify when a specific event occurs. Instead of polling the API to check for new bounces, the platform pushes the event to you as it happens. Webhooks are the standard way to receive real-time email event data.
Common Email Webhook Events
- delivered: Message accepted by the receiving server
- opened: Tracking pixel loaded (subject to MPP limitations)
- clicked: Link in email was clicked
- bounced: Temporary (soft) or permanent (hard) delivery failure
- complained: Recipient marked email as spam via FBL
- unsubscribed: Recipient clicked the unsubscribe link
- dropped: Email was rejected before sending attempt
Why It Matters
Webhooks enable real-time list cleansing (immediately suppress bounces), dynamic content updates, and live dashboards. They are more efficient than polling because data arrives instantly rather than waiting for the next API check.
Related Glossary Terms
BIMI
BIMI (Brand Indicators for Message Identification) is an email standard that allows brands to display their logo next to their emails in supported email clients. It requires DMARC enforcement at quarantine or reject policy.
Customer Data Platform (CDP) for Email
A customer data platform (CDP) is a system that unifies customer data from multiple sources into a single profile, enabling advanced email personalisation, segmentation, and cross-channel coordination.
Email Deliverability
Email deliverability is the ability to land in the recipient's inbox rather than the spam folder. It depends on sender reputation, authentication, list quality, and content practices.
Email Alias
Alternative email addresses or subaddressing patterns that forward to a primary mailbox, affecting subscriber identity tracking and deduplication in email marketing.
Email API Key Management
Email API key management covers creating, storing, rotating, and revoking API credentials used to connect email platforms, ensuring security while maintaining reliable integration access.
Email API Rate Limits
Email API rate limits control the volume and frequency of requests to an ESP's API endpoints, protecting infrastructure from abuse and ensuring fair resource allocation across all customers.