Say goodbye to constantly polling our API for updates! With webhooks, you can subscribe to updates for a whole range of events in Helo—and we’ll automatically notify you when those happen. 

Here are the events you can set up webhooks for: 

  • Sending: Get notified when a message you sent was accepted, processed, delivered, or bounced. 
  • Engagement: Know when a message was opened or clicked
  • Recipient feedback: When a recipient complained, unsubscribed, or resubscribed, we can let you know about those events right away. 
  • Domain setup: Receive webhooks for all events that are relevant for domain setup and verification, including domain-key-verified, domain-key-verification-failed, return-path-domain-verified, and return-path-domain-verification-failed. 


Depending on your needs, you can set up webhooks for a single event type or subscribe to them all. Plus, if you’re using Channels to separate your mail sending, you can scope your webhooks to individual Channels as well. 

To learn more about webhooks, how to set them up, and what we do in case we don’t receive a response from you when we send a webhook, read the webhooks docs.

Want an event we don’t support yet?

Let us know about it! Just send us a quick note at support@helohq.com and tell us what’s missing.