Knowledge base


Webhooks allow you to subscribe to real-time notifications about various events that occur in MailerSend.

Listen for events on your MailerSend account so your integration can automatically trigger reactions. You can create a webhook directly from your account.

For example, an HTTP POST callback is sent to your provided URL with a payload about the sent email. It allows you to get the most recent updates without constantly polling the API.

Add a webhook to your domain

To create a webhook, follow these steps:

  1. Go to the Domains page, find the Webhooks section and click on Add webhook.

  2. Complete the form by entering the endpoint URL you wish the information to be sent to and your webhook name.

  3. Select the events you would like to listen to, or click on receive all events if you wish to listen to them all: Delivery, Soft bounce, Hard bounce, Open, Click, Unsubscribe, Spam complaint.

  4. Click on Save webhook and you’re done!

add a webhook for transactional emails

Once you have saved your webhook, you can copy your secret webhook key to your receiving app. You can find this on the webhook management page.

You also can pause the webhook by clicking on Edit and then on the Status toggle, moving it from Enabled to Disabled.

Webhook details

How to test a webhook

On the webhook management page, you can monitor the attempts your webhook has made to reach your URL endpoint, and check for any discrepancies in the last 7 days. If you need to generate URL endpoints to test the webhook, we recommend these tools: and

Test your webhook by sending an email, following the steps specified here. Depending on the events, you should receive a notification with the event type.

About webhook attempts

Webhook attempts log

You can consult all webhook attempts that have been made in the last 7 days in the Webhook attempts section of your webhook description page.

When your webhook receives a response other than a 2xx code from your endpoint URL, or if the endpoint doesn’t respond within 3 seconds, it will show up as a failed attempt in the log section of your webhook. If it receives a 2xx, then it will show as a success.

If a webhook call fails, MailerSend will retry the call a couple of times, waiting 10 seconds between the first and second attempt and 100 seconds between the second and the third attempt to avoid hammering the application you want the information sent to.

Need more info?

Please feel free to contact us at and a member of our support team will gladly assist you.

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