Domain keys and how they work

Like any good email service provider, we integrate with larger email hosts such as Hotmail and AOL to provide their customers with a feedback loop. This means that emails sent by us to these hosts include a 'Mark as spam' button which, if clicked, sends a message back to us to tell us which message was marked as spam or junk, so we can ensure the subscriber is swiftly and permanently unsubscribed from that mailing list.

Some email hosts, such as Yahoo, don't use such a feedback loop, but instead use a service which requires domain keys. Domain keys, or DKIM, work by adding a digital signature to any outbound mail from our system stating that it has come from us on your behalf. 

When you create an email campaign in your account, you can choose your own email address to appear as the 'from' address in the inbox. When the campaign reaches the email host, however, it will check the full sending information and find that it's actually come from our servers. This practice is known as 'white-hat spoofing' - that is to say, we send an email pretending to be you. In order for the email to be accepted, we need to let the email host know that we're doing this with your blessing. 

In order to correctly sign that email, we use domain keys to state that we are sending the email from our domain on your behalf. While the email itself is not affected, there is a slight change to the way the email 'from' details are displayed in some email clients, such as Outlook.

If, for example, you were sending an email from a account called "Epic Pets", you might use the address "" as your 'from' address. When you open up the email, the 'from' details would be displayed like this:

The actual 'from' domain is one of our own, "". It uses your account name as the precursor of this, so that the 'from' details are still recognisable as your company. And it adds that the email has come on behalf of the full 'from' address you originally selected, so that your subscribers can still see exactly who has contacted them.

Often we're asked if there's anything we can do to change the way this is displayed, but unfortunately it's the only way campaigns can be delivered and displayed reliably in Outlook. In fact, we encourage the use of domain keys as they make it more likely for your subscribers to receive your emails successfully. However, it isn't something to worry about because:

  • All of the information is still presented accurately and clearly to the subscriber
  • Many other email servers use this system, so subscribers will likely receive other emails in this format
  • Almost no other email clients display this information, so subscribers using clients like Gmail or Thunderbird will only see your chosen 'from' address

Using this system we're able to improve delivery to all email hosts and ensure that your subscribers receive your emails and can still clearly see who they're from. 

Powered by Zendesk