How we achieved 10/10 email deliverability

The independent mail‑tester.com service gives an email sent through eNudge a 10/10 score for deliverability (01/07/2019). This article describes how we did it — and, importantly, how you can too.

A continual battleground

Email deliverability is a continual technology battleground. The war between spammers and con artists and those trying to deliver safe, legitimate emails means the weapons needed to combat the enemy are regularly enhanced. Unfortunately, the business that simply needs its message received by its customers becomes the innocent civilian caught in the ongoing battle.

At eNudge we constantly review the delivery of emails into the inbox. Our 10/10 result required the following more recent configuration changes.

What we configured

• DKIM. A private/public key pair is attached to our sending domain, and the private key signs every outgoing email — so the receiving gateway can verify both that the sender is authorised to send on behalf of the domain, and that the message wasn't tampered with in transit.
• DMARC. Works alongside DKIM; every sender should set up a DMARC record to receive reports on potential abuse of their emails. You can read more in this article on DKIM and DMARC.
• TLS. Transport Layer Security encrypts emails — otherwise plain text and subject to eavesdropping — while they're in transit. Read more about TLS for email. All emails sent via eNudge are now encrypted using TLS.
• List‑Unsubscribe header. Gmail and Outlook look for the list‑unsubscribe header embedded in every eNudge email and present it at the top of the message (it was already in the footer). Making the Unsubscribe button easy to reach reduces the likelihood that recipients complain by clicking ‘spam’ instead — and that's treated positively for inbox delivery.
• Alt text on the open‑tracking image. To register that an email has been opened, we track the download of a special image. To keep the code small, that image originally had no alt text — which caused a very small reduction in the delivery score. A blank alt text field is now included.

If you don't yet have a DKIM associated with your emails, don't hesitate to get in touch and we'll help you with certificate setup. And if you'd like to discuss how eNudge can help you achieve a perfect delivery score, please contact us.