Set up DMARC and see who's sending email using your brand's domain.

How can I confirm delivery of a message?

When it comes to troubleshooting emails, you have several tools at your disposal. For instance, you can search activity to see if a message was sent, bounced, marked as spam, or even if it is still in queue. However, sometimes a message has been marked as “processed” but your customer never received it.

In order to verify when and how a message was delivered to a customer it is important to see the actual interaction between mail servers. With Postmark, you can see the exact remote mail server response for each message in activity. For instance, if you sent an email to an address on, the response might look like this:

  smtp;250 2.0.0 OK 1436801113 x3si14160585iod.35 - gsmtp
  From: (

This will show you that the message was accepted (250 OK) by the server at “” at gmail. It’s a confirmation that gmail accept the message from our mail servers.

When troubleshooting email, this goes a long way. If you are talking to a customer who is having trouble getting your emails, you can now align this confirmation with the logs that the customer might have on their own mail server. This allows you to focus on delivery with the specific email provider or company instead of wondering if the email bounced or never even made it to the remote mail server.

There are a few things you can discover from delivery confirmations:

  1. How long did it take for the email to be accepted by the remote server?
  2. Was it sent to the correct mail server or was DNS cached to the wrong MX record?
  3. Which server accepted the message and when?

Of course, we also understand that the last thing you want to do is align mail server logs with customers. These delivery Confirmations will help us in support as we troubleshoot email delivery issues with you. It gives you clear information about what happened and when so you we can help you resolve issues faster.

Understanding email delays and issues — keeping us transparent

You may have noticed that this potentially point out flaws in Postmark. For instance, what if we are throttling messages to ISPs too much where it delays delivery? What if the reputation of one of our IPs went down and an ISP backed off on accepting messages? Or what if our DNS cache was outdated and we sent to the wrong mail server?

These are all things that could happen. Instead of hiding it, we are committed to making this loud and clear. As an ESP, it’s our responsibility to put display our successes and failures front and center. With Delivery Confirmations, you get a clear view of email delivery for your messages. Not only do we want you to see this, we want you to reach out and keep us responsible for improving if things do go wrong.

It’s our job to be the most reliable transactional email platform for your business or product, not just in terms of availability and uptime, but delivery and support as well. Delivery Confirmations will help uphold this mission and give you more control and visibility into your email delivery.

Last updated June 11th, 2020

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