New and Improved SMTP Header REST API Endpoint

Devs and Quality Assurance Testers Can Easily Validate Mail Headers

The SMTP header endpoint provides quality assurance testers with the option to view an email message’s SMTP headers in parsed formats that easily integrate with automated testing frameworks.

Problem

Developers and QAs are often asked to validate contents of emails. This can include from address, links, and subject. For many organizations this can be a manual process of checking the email and validating if the test criteria has been met.

Solution

Mailsac’s new message header endpoint provides SMTP headers in 3 formats:

1. JSON object format, grouped by lowercased header key. This format is easily consumed by industry standard tools such as Selenium.

{
  "received": [
    "from 107.174.234.77 by frontend1-172-31-29-224 via 172.31.42.57 with HTTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon Dec 24 2018 15:29:06 GMT+0000 (Coordinated Universal Time)",
    "from 107.174.234.77 by smtp-in2-172-31-42-57 via 172.31.23.10 (proxy) with SMTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon, 24 Dec 2018 15:29:06 UTC",
  ],
  "from": [
    "[email protected]"
  ],
  "to": [
    "[email protected]"
  ],
  "subject": [
    "invitation to collaborate"
],
  "date": [
    "Mon, 24 Dec 2018 15:29:06 +0000"
  ]
}

2. Ordered JSON array format. This formats pre-parses the headers, but maintains the original order, while still handling duplicate headers such as Received.

?format=ordered-json

[
  {
    "name": "received",
    "value": "from 107.174.234.77 by frontend1-172-31-29-224 via 172.31.42.57 with HTTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon Dec 24 2018 15:29:06 GMT+0000 (Coordinated Universal Time)"
  },
  {
    "name": "received",
    "value": "from 107.174.234.77 by smtp-in2-172-31-42-57 via 172.31.23.10 (proxy) with SMTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon, 24 Dec 2018 15:29:06 UTC"
  },
...
  {
    "name": "to",
    "value": "[email protected]"
  },
]

3. Plaintext original format. This format is useful when you are interested in parsing or inspecting the email headers yourself, and do not wish to download the entire message.


?format=plain

Received: from 107.174.234.77 by frontend1-172-31-29-224 via 172.31.42.57 with HTTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon Dec 24 2018 15:29:06 GMT+0000 (Coordinated Universal Time)
Received: from 107.174.234.77 by smtp-in2-172-31-42-57 via 172.31.23.10 (proxy) with SMTP id 8m7iqeiZKJ3MzwTwUQlU for <[email protected]>; Mon, 24 Dec 2018 15:29:06 UTC
...
To: [email protected]

“We are currently using the REST API headers endpoint in support between our own microservices. Our POP3 server fetches headers of message to implement the POP3 TOP command.” — Michael Mayer, Partner Forking Software LLC

Getting Started

The message header endpoint /api/messages/:messageId/headers is available on all Mailsac plans (including our free tier). See our API Specification for more information.

This code example could can be modified to view the headers for the first email message on an inbox [email protected]. Make sure to insert your API Key and change the email address to an email address you which is public or reserved by your account.

const superagent = require('superagent') // npm install superagent

const mailsac_api_key = 'YOUR_API_KEY_HERE' // change this!

superagent
  .get('https://mailsac.com/api/addresses/[email protected]/messages')
  .set('Mailsac-Key', mailsac_api_key)
  .then((messages) => {
      const messageId = messages.body[0]._id
      superagent
          .get('https://mailsac.com/api/addresses/[email protected]/messages/' + messageId + '/headers')
          .set('Mailsac-Key', mailsac_api_key)
           .then((response) => {
               console.log(response.body)
           })
  })
  .catch(err => console.error(err))

/**
{
  received: [
    'from [ by fireroof via ::1 with HTTP id bo4xdVji_oqEixBO0gGLbvIoe for <[email protected]>; Wed, 28 Oct 2020 23:05:29 GMT',
    'from [ fireroof with SMTP id bo4xdVji_oqEixBO0gGLbvIoe for <[email protected]>; Wed, 28 Oct 2020 16:05:29 PDT'
  ],
  'x-mailsac-inbound-version': [ '' ],
  date: [ 'Wed, 28 Oct 2020 16:05:29 -0700' ],
  to: [ '[email protected]' ],
  from: [ '[email protected]' ],
  subject: [ 'test Wed, 28 Oct 2020 16:05:29 -0700' ],
  'message-id': [ '<[email protected]>' ],
  'x-mailer': [ 'swaks v20190914.0 jetmore.org/john/code/swaks/' ]
}
**/

Multi-User Login using API Credentials, For Team Collaboration

Update: April 2021 – Multi-User login is now called “Sub-Accounts”

Named API Keys can now be used as website authentication.

Custom domains and Private Addresses have been great for quality assurance teams to conduct end to end automated testing of email. But sometimes interacting with an REST API can be a lot of overhead for non-repeating tasks. API Credentials can now be used to login to the website.

All private addresses and custom domains associated with the primary account will be visible from the website for API users. The permissions for API users are the same as API keys.

Quality assurance teams often share credentials of test accounts for the web application they are testing. These test accounts might to be associated with an email provisioned by their IT department or the QA tester’s personal email. Mailsac private domains allow the test accounts to be created in an an environment all members of the QA team have access to.

This feature allows teams to work together in the Mailsac platform. There is no longer a need to for each person to have their own Mailsac account. A named API Key can be created for each person. That API key can be used to interact with the REST API and the website. As a result, password resets and transaction emails sent to a Mailsac private domain can be accessed by any member of the QA team.

“Internally we have used Mailsac for collaboration. Being able to share a private address or domain allows my team members to see exactly what I am seeing. This feature allows our customers to do the same with their own private domains and addresses” Michael Mayer – Member – Forking Software LLC

Getting started is as easy as provisioning a new set of API credentials and enabling the website login on the API Key. This can be done the the Dashboard and selecting API Credentials & Users

Enable Website Login

We will be rolling this feature out to our Business and Enterprise Plans in the next couple weeks. If you have an immediate need for this feature we can enable it on your account. Contact [email protected] to get early access to this feature on you Business or Enterprise Plan.

Announcing the Email Capture Service

With email capture, Quality Assurance teams testing email delivery can easily see the exact emails customers will receive.

The new Email Capture Service is an SMTP server that accepts all mail regardless of the To and From address. It is similar to Mailsac’s existing disposable mail, with some key differences. The capture service acts like a fake outbound relay, rather than a fake inbound relay.

Messages sent via capture.mailsac.com are available for viewing from the Mailsac Website or REST API. This allows Quality Assurance teams to validate that the message was sent and the contents of the message.

Web applications frequently send transactional emails to users. During development and User Acceptance Testing, sending email is disabled in the application – so emails are not accidentally sent to customers or fake test addresses. Sending lots of bounces from a development application is a great way to get your domain blacklisted, greylisted, or onto a spam list.

Send via capture.mailsac.com instead

Web applications can be configured to use the Email Capture Service as their SMTP server. Emails sent by the application can then be viewed by developers and testers.

Customers have been sending test emails to hosted custom domains at Mailsac for years. The email capture services simplifies the process of sending emails to Mailsac by allowing developers to relay through Mailsac without any additional email infrastructure.

Michael Mayer – LLC Member at Forking Software LLC.

Most customers can get started sending through the Email Capture service instantly.
Wherever you input SMTP credentials in your application, change to the following:

  • Server Name: capture.mailsac.com
  • Port: 5587
  • Use Secure Connection: Yes (TLS)
  • User Authentication – Username: Mailsac account username *
  • User Authentication – Password: any Mailsac API Key for the account

Any email sent to the capture server will be available at the TO address in Mailsac’s UI or API.

* a private address or custom domain address may be used if your email library does not support a separate FROM address for the username.

Further Reading

Easy purging of inboxes

We’ve listened to your feedback. This week we released new functionality to delete all the messages in an inbox.

Purging an inbox can be accomplished in two ways:

  • programmatically, via the REST API DELETE /api/addresses/:email/messages route
  • by clicking the new “Purge Inbox” button

Here’s an example of clicking the Purge Inbox button, instantly recycling over 80 messages:

Why were all the messages not deleted?

Starred messages (savedBy in the REST API) will not be purged.

We recommend un-starring those messages first, then purging the inbox, if you want to completely clear the inbox. Or, use the existing single-message deletion feature will allow you to delete a starred message. There is a button for deleting messages on the inbox page. The REST API route to delete a single message is DELETE /api/addresses/:email/messages/:messageId.

REST Compliant Response From Email Validation API

The GET Method on the REST API endpoint /api/validations/addresses/:addressToValidate has been updated to return a JSON object. Previously, this endpoint was returning an array. The POST Method response remains unchanged.

An example GET request and response has been added to the Mailsac REST API documentation.

Email validation via the Mailsac Website is still available to all registered customers. An email address can be checked for valid format and if it is associated with any known disposable email services.

Slack Webhook Integration with Private Email Addresses

Last year, we soft-launched a new forwarding feature on private addresses. You may have noticed – underneath the “Forwarding” section, there is now a Forward to Slack option. (Manage Addresses > Settings > Forwarding)

With only a little clicking, you can have inbound emails dumped into a Slack channel. It’s easy – no coding, and no servers, are necessary.

We built this feature because we use Slack internally, and had a custom webhook translator to send certain emails to a channel. After a little copy and paste, code massaging, and unit testing, we were able to get the feature into the platform.

Email → Slack Options

After inserting a valid Slack Webhook URL, we give you the option to enable the To and From address to display in the Slack message (Include To and From in the slack message checkbox).
Here’s the difference:

Screenshot from slack receiving an email from Mailsac
Disabled TO and FROM in Slack Message
Enabled FROM and TO in Slack Message from Email

Enabling TO and FROM is useful for support requests, shared email inboxes, or when you might have multiple inboxes pointed at the same channel.

Disabling TO and FROM is useful for receiving alerts or notifications from the same service. For example, if you send a notification about a new purchase on your website to a Slack channel, and it always comes from the same service email address, you don’t need it to take up space in the Slack message.

Email Images and Attachments to Slack

The email-to-Slack forwarding feature supports file attachments, including images. Images will be displayed inline.

We recommend archiving attachments outside Slack at this time. Attachments are subject to recycling. Also, attachments must be made public in order for Slack to accept the messages. So do not send any PII or sensitive information. This is another reason why we chose to recycle attachments.

The same Mailsac message size limits apply for Slack. If you are interested in bumping up the attachment sizes, make a feature request or contact support and include your account ID.

Debugging Forwarding

The mail activity log will show forwards, and reports failures posting to Slack with error messages. (Dashboard / Usage / Recent Mail Activity Log)

Debug logging on email webhooks to Slack. Response data is redacted.
On errors, you will see Slack’s response.

Feedback

As always, please post feedback and questions to the Mailsac Discussion Forum. We think the feature is useful as-is, but we are open to making changes to better meet our customers needs.

Read more about the email-to-Slack webhook on our docs site.

New Feature: Debug Mail Activity and Publishing

A new feature allows viewing recent activity across the account – inbound email messages, web socket publishing, webhooks, and Slack webhook posts.

From the dashboard, go to Usage & Analytics, then Recent Mail Activity Log.

The debug log shows all inbound, outbound, and publishing actions by 15 minute intervals. Business Plans and higher get access to at least 6 months of history. Free and Indie Plans can see the most recent 15 minutes.

We intend to continue improving this feature by including extended debugging information, response codes, bounces, and other useful information. Please share your experiences with us, and report any problems.

This is a good time to mention you can view have inbound and outbound message counts and bandwidth, up to 30 days currently visible.

This tool helps make it easier to understand how many messages your app is sending – whether it is a custom email app built atop Mailsac, or QA integration testing team.

New Delete Messages Flag When Releasing a Private Email Address

When releasing a private address, there is now an option to “empty the inbox” – deleting all messages associated with the private address. You can find the option by clicking the settings button when managing your private addresses.

The API endpoint DELETE /api/addresses/:email now supports the query string deleteAddressMessages. When deleteAddressMessages=true is passed, all messages associated with the inbox will be deleted.

Please note that all messages are deleted, including starred/saved messages. It is immediate and irreversible.

Brand New Look To Dashboard

The Mailsac dashboard has a brand new look. Our commonly used services are easier discover. You may find out about features you never new existed.

Setting up disposable or test email for a domain has never been easier. With the Mailsac Zero-Setup-Subdomain, choose you subdomain name and start receiving emails within minutes.

We do our best to build simple, indispensable APIs and tools for Quality Assurance teams. End to end testing of emails sent by web applications is easy with Mailsac. API Keys are included with all Mailsac accounts, including our free tier with generous API call limits.

Increase your privacy by using the Mailsac’s free disposable email service. Send to virtually any @mailsac.com address and view the email without ever signing in. To see all messages in an inbox and to view images you will need to sign up for a free account. With the free account you can star messages you need to keep and make them hidden to other users. If you find yourself needing extra email addresses that nobody else can see. They are available as an addon.