Webhook Forwarding

Emails sent to Private Email Addresses (or Catch-All addresses) can be forwarded to a URL also known as a webhook.

Configure Webhook


Select Manage Email Addresses from the Dashboard. Choose Settings next to the email address. In the Forward to Custom Webhook setting enter the webhook address and select Save Settings

Configure webhook forwarding on private address using curl
curl -H "Mailsac-Key: YOUR_API_KEY_HERE" \
     -H "Content-Type: application/json" \
     -X PUT https://mailsac.com/api/private-address-forwarding/bclinton@mailsac.com \
     --data '{"webhook": "https://mywebsite.com/webhooks"}'

# Curl Output
  "_id": "bclinton@mailsac.com",
  "owner": "mailsac_user",
  "forward": null,
  "enablews": false,
  "webhook": "https://mywebsite.com/webhooks",
  "webhookSlack": null,
  "webhookSlackToFrom": null,
  "catchAll": null,
  "password": null,
  "info": "",
  "created": "2020-08-19T23:31:15.664Z",
  "updated": "2020-08-25T13:59:05.430Z"
Configure webhook forwarding on a private address using Node.js. requires npm install superagent
const superagent = require('superagent')

  .set('Mailsac-Key', 'YOUR_API_KEY_HERE')
      webhook: "https://mywebsite.com/webhooks"
  .then((res) => {
  .catch(err => {

  { _id: 'bclinton@mailsac.com',
  owner: 'mailsac_user',
  forward: null,
  enablews: false,
  webhook: 'https://mywebsite.com/webhooks',
  webhookSlack: null,
  webhookSlackToFrom: null,
  catchAll: null,
  password: null,
  info: '',
  created: '2020-08-19T23:31:15.664Z',
  updated: '2020-08-25T14:04:34.261Z' }
Configure webhook forwarding on a private address using Python.
import requests
from pprint import pprint

headers = {'Mailsac-Key': 'YOUR_API_KEY_HERE'}
url = 'https://mailsac.com/api/private-address-forwarding/bclinton@mailsac.com'
data = { 'webhook':'https://mywebsite.com/webhooks' }

r = requests.put(url, data=data, headers=headers)
{'_id': 'bclinton@mailsac.com',
 'catchAll': None,
 'created': '2020-08-19T23:31:15.664Z',
 'enablews': False,
 'forward': None,
 'info': '',
 'owner': 'mailsac_user',
 'password': None,
 'updated': '2020-08-25T14:11:14.695Z',
 'webhook': 'https://mywebsite.com/webhooks',
 'webhookSlack': None,
 'webhookSlackToFrom': None}

Webhook Sample JSON

This is an example of the JSON that will be passed to the Webhook URL.

{"text": "this is a message",
"headers": {
     "dkim-signature": "redacted",
     "received": "2017-05-01T05:22:03.000Z",
     "content-type": "text/plain",
     "from": "mastadon@mailsac.com",
     "to": "gemini@mailsac.com",
     "subject": "",
     "message-id": "",
     "list-unsubscribe": "",
     "content-transfer-encoding": "7bit",
     "date": "Wed, 1 May 2017 05:22:03 +0000",
     "mime-version": "1.0"
"subject": "twin",
"messageId": "MS-5412430010104145004240335343@mailsac.com",
"priority": "normal",
"from": [{
     "address": "mastadon@mailsac.com",
     "name": ""
"to": [{
     "address": "gemini@mailsac.com",
     "name": ""
"date": "2017-05-01T05:22:03.000Z",
"receivedDate": "2017-05-01T05:22:03.000Z",
"originalInbox": "gemini@mailsac.com",
"inbox": "gemini@mailsac.com",
"domain": "mailsac.com",
"encryptedInbox": "inbox-db54b7f5f09041165aaaaae5ca9557c806cf3d95f8",
"raw": "DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailsac.com;\r\n q=dns/txt; s=mailsacrelay;\r\n bh=redacted;\r\n h=from:subject:to:mime-version:content-type:content-transfer-encoding:list-unsubscribe;\r\n b=redacted\r\nReceived: from localhost ( by mailer with SMTP; Wed May 1\r\n 2017 01:22:03 GMT-0400 (EDT)\r\nContent-Type: text/plain\r\nFrom: mastadon@mailsac.com\r\nTo: gemini@mailsac.com\r\nSubject: twin\r\nMessage-ID:\r\n \r\nList-Unsubscribe: \r\nContent-Transfer-Encoding: 7bit\r\nDate: Wed, 1 May 2017 05:22:03 +0000\r\nMIME-Version: 1.0\r\n\r\this is a message",
"received": "2017-05-01T05:22:04.851Z",
"_id": "IhnBcuaaiC",
"ip": ""

Webhook contents are very similar to web socket emails.

Read more about JSON Webhooks at the API Reference


If the Webhook forwarding is not working, additional debugging information is available in Recent Activity.