Deprecation of Outbound SMTP Service

Outbound SMTP service will no longer be supported by Mailsac.

What Does this Mean for Me?

Mail will no longer be able to sent from Mailsac addresses or custom domains using the outbound Mailsac SMTP service.

If you are sending from the REST API, compose email form, or Unified Inbox we encourage you to seek out other SMTP sending services. Mailsac has always supported direct SMTP from anywhere, without a mail relay, as well.

Reasons for the Change

Email delivery is not an easy problem at scale.

Our customers, especially quality assurance teams, are using Mailsac as a receive-only service.

The likelihood that Mailsac’s outbound messages are delivered to the intended inbox has been trending lower over time, despite increased effort.

We made the decision to focus our efforts on improving our core product – disposable inbound email for testing.

Recommended Providers of Outbound SMTP Service


Deprecation of Mail Transfer Agent on mailsac.com Top Level Domain

What is changing?

Mailsac will no longer act as a mail transfer agent using the top level domain mail server mailsac.com. That means mail sent to the mail server mailsac.com on port 25 will no longer be accepted.

This change will go into effect on October 9th 2021.

Am I affected?

Almost certainly not. This is a legacy configuration that has not been published or referenced in any communication for several years. Our logs indicate this feature has not been used as far back as logs are stored.

Customers who setup a custom domain are sent instructions to use the mail servers in.mailsac.com and alt.mailsac.com during the initial configuration of their domain.

Instructions on our website for custom domains or the free hosting option instruct customers to use in.mailsac.com and alt.mailsac.com for their MX records. This has been the case for several years.

Why is this being deprecated?

Receiving mail using a mail transfer agent on the top level domain limits our ability to further scale our highly available mail services.

How can I verify I am not affected?

The DNS verification section of the docs can walk you through the process.

For those familiar with MX records, se the command line tool dig or a web based dig tool to verify your MX records are in.mailsac.com and alt.mailsac.com. If your MX records point to mailsac.com you will need to update them to use in.mailsac.com and alt.mailsac.com

dig example

Use the dig comand dig MX <domain_name> to view the MX records for a domain. In the answer section the hostnames in.mailsac.com and alt.mailsac.com should be listed.

Web based dig

The web based dig tool can be used to verify MX records for a domain. The MX records should show in.mailsac.com and alt.mailsac.com

Scheduled Database Maintenance May 22, 2021

Our team will be performing database maintenance on Saturday May 22nd, 2021 from 14:00 – 16:00 UTC. During this period, API, email, and website services may be unavailable, intermittent, or slow to respond.

Updates during and on completion of the maintenance will be provided in this blog post.

UPDATE
All maintenance has been completed and the team is standing by monitoring performance. No further impact is expected.

Spring Cleaning with Mailsac API

My garden has been planted and the days are getting warmer. Next task, cleaning up. Mailsac won’t help you organize you garage or avoid the accumulation of clutter. But it can help you get rid of old emails.

The Delete All Messages in a Domain Endpoint released on March 23, 2021 can help you keep your private domain storage under the storage limit. It’s useful for deleting all messages before running integration tests.

This post will detail the different methods of bulk message deletion.

Cleanup a Custom Domain

All messages in a custom domain can irrevocably be deleted.

From the Dashboard select Custom Domains Select Domain to Mange → Advanced tab → Irreversibly Delete Email

The REST API has a commensurate endpoint for deleting all messages in a domain. It can be invoked by calling an HTTP POST https://mailsac.com/api/domains/{domain}/delete-all-domain-mail , where {domain} is the custom domain.

Cleanup a Private Inbox

All messages in a Private Inbox can be deleted from the website or the REST API. Both methods will not delete starred messages.

From the From the Dashboard select Manage Email Addresses Select Email Address Purge Inbox

Messages in a Private Inbox can be deleted using the endpoint for deleting messages in a private inbox. The endpoint can be used with the HTTP DELETE method on https://mailsac.com/api/addresses/{email}/messages where {email} is the private email address.

Deleting Individual Messages

Individual messages can be deleted from both private and non-private inboxes.

From the From the Dashboard enter an inbox in the inbox viewer form and select Check The Mail!. From the Inbox, Click the message → Select Delete Permanently Delete

Individual messages can be deleted using the delete message REST API. The endpoint can be called using an HTTP DELETE with the URL https://mailsac.com/api/addresses/{email}/messages/{messageId} . The {email} parameter is the email address and the {messageId} is identifier for the message to be deleted. The messageId can be found by using the list messages in an inbox REST API endpoint.

Improved SMTP Relay Logs

The Recent Activity Log now includes detailed sender and delivery information for outbound email. This empowers customers to diagnose sending issues.

Successful Email Log Entry

The screenshot below shows a successful email delivery sent from user2@mailsac.com to user1@mailsac.com. The email message id, number of delivery attempts, rejection status, and time stamps are included in the logs

Failed Email Log Entry

The screenshot below shows a failed email delivery from somebody@mailsac.com. The message id, number of attempts, timestamp, and error message are provided.

This error message indicates that the recipients domain no-where-no-where-no-where.info does not exist.

Industry Standard API Documentation

Mailsac API Documentation has been converted over to use OpenAPI.

Code Examples

The new format gives developers and quality assurance testers code samples for common programming languages (curl, Node, Python, PHP, Go, etc).

Explore the API Using Swagger UI

The API can be explored without writing any code using the Swagger UI Explorer. All that is needed to get started is a free Mailsac API Key (requires sign up).

In the Swagger UI Explorer, choose the Authorize button and enter your Mailsac API Key


Use the “Try it out” button to interact with any of the REST API endpoints. A curl example, request URL, response body, and headers are provided.

New Features Available On All Plans

All of our plans now included additional features. These features will help quality assurance teams and individual developers test sending and receiving of email, and easily share non-production email accounts.

To see a complete listing of feature visit see our pricing page.

We are in the process of rolling out these features to our existing customers. Please contact support@team.mailsac.com if you need access to the features ahead of our scheduled roll out.

Free Plan

Old PlanNew Plan Feature / Limit
N/AEmail Capture
N/AWebhook Forwarding (requires private inbox)
N/AWebSocket Forwarding (requires private inbox)
N/APurge Inbox (requires private inbox)
N/ASlack Webhooks (requires private inbox)
N/ACommunity Support

Indie Plan

Old PlanNew Plan Feature / Limit
10 Private Addresses50 Private Addresses
0 Outgoing Messages500 Outgoing Messages (non-recurring)
N/AEmail Capture
N/AMessage Logs (15 minutes)
N/ADelete all messages by domain

Business Plan

Old PlanNew Plan Feature / Limit
50 Private Addresses250 Private Addresses
0 Outgoing Messages2,500 Outgoing Messages (non-recurring)
N/AWebsite Login using API Key (2 users)
N/AMessage Logs (1 month)

Enterprise Plan (New Plan)

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 <cd@mailsac.com>; 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 <cd@mailsac.com>; Mon, 24 Dec 2018 15:29:06 UTC",
  ],
  "from": [
    "grem@hello.msdc.co"
  ],
  "to": [
    "cd@mailsac.com"
  ],
  "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 <cd@mailsac.com>; 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 <cd@mailsac.com>; Mon, 24 Dec 2018 15:29:06 UTC"
  },
...
  {
    "name": "to",
    "value": "cd@mailsac.com"
  },
]

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 <cd@mailsac.com>; 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 <cd@mailsac.com>; Mon, 24 Dec 2018 15:29:06 UTC
...
To: cd@mailsac.com

“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 calendartrinity@mailsac.com. 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/calendartrinity@mailsac.com/messages')
  .set('Mailsac-Key', mailsac_api_key)
  .then((messages) => {
      const messageId = messages.body[0]._id
      superagent
          .get('https://mailsac.com/api/addresses/calendartrinity@mailsac.com/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 <calendartrinity@mailsac.com>; Wed, 28 Oct 2020 23:05:29 GMT',
    'from [ fireroof with SMTP id bo4xdVji_oqEixBO0gGLbvIoe for <calendartrinity@mailsac.com>; Wed, 28 Oct 2020 16:05:29 PDT'
  ],
  'x-mailsac-inbound-version': [ '' ],
  date: [ 'Wed, 28 Oct 2020 16:05:29 -0700' ],
  to: [ 'calendartrinity@mailsac.com' ],
  from: [ 'bclinton@mailsac.com' ],
  subject: [ 'test Wed, 28 Oct 2020 16:05:29 -0700' ],
  'message-id': [ '<20201028160528.2893005@fireroof>' ],
  'x-mailer': [ 'swaks v20190914.0 jetmore.org/john/code/swaks/' ]
}
**/