CATEGORY: Best practiceDeliverability

Deliverability 101

Deliverability 101

Deliverability, also known as inbox placement, is a step before the usual open and click-through metrics that we marketing professionals determine our success by.

To achieve optimum deliverability there are four important factors that you need to consider.
1. Identity
2. Reputation
3. Content
4. Measurement


The recipient’s mailbox provider needs to be able to confirm your true identity as the sender and differentiate you from spammers. Authentication protocols usually include DKIM, SPF and DMARC.

  • SPF – Sender Policy Framework – A Domain Name Server (DNS) record that says an IP or domain can send email on your behalf. SPF enables the owner of a domain to specify which mailservers are authorised to send mail on its behalf. The receiving mail server will check the sending server’s identity against the SPF record and will accept or reject it based on the result.

  • DKIM – DomainKeys Identified Mail – Also known as “digital signature,” this is a method for associating a domain name with an email message, allowing a person, role, or organization to claim some responsibility for the message. A digital signature gives recipients a reason to believe the email message was created by a known sender and was not altered in transit.

  • DMARC - Domain Message Authentication Reporting and Conformance – Ensures that emails meet SPF and DKIM requirements before they are delivered.

If you can’t prove your identity, or your recipient’s email address or domain name aren’t valid, or even if your IP address/domain has been blocked, then your email is likely to bounce. This means it can’t be delivered to the recipient’s email address.

A Hard bounce is a permanent failure to deliver an email usually due to the email address not existing, being invalid, or being blocked. Email addresses that result in hard bounces can negatively impact deliverability and should be removed from your email lists.


An email sender reputation is a score that an Internet Service Provider (ISP) assigns to an organization that sends email. It’s a crucial component of your email deliverability. The higher the score, the more likely an ISP will deliver emails to the inboxes of recipients on their network. If the score falls below a certain threshold, the ISP may send messages to recipients’ spam folders or even reject them outright. Several factors can go into determining the score, including:

  • The amount of email sent by the organization

  • How many recipients mark the organization’s emails as spam or otherwise complain to the ISP about the messages

  • How often the organization’s emails hit the ISP’s spam trap

  • The organization’s inclusion on different blacklists

  • How many of the organization’s emails bounce because they were sent to unknown users or for other reasons

  • How many recipients open, reply to, forward, and delete the organization’s messages, as well as click the links found in them

  • How many recipients unsubscribe from the organization’s email list

Each ISP decides which factors to include in its sender reputation and how heavily it weights those factors when calculating the reputation for each organization that sends email to some of its users. A sender could have varying reputation scores for different ISPs. If a sender has multiple domain names and sends email from different IP addresses, each one will have its own sender reputation.


As marketers, this is the part of the email journey that we dedicate the most time and attention to.  Crafting our subject lines, agonising over our text and calls to action aiming to create a beautiful engaging email that our recipients will love. Avoiding overtly salesy language and spammy content with crazed punctuation or all CAPS we all recognise as best practice, but the best way to really see how well your email would perform and the words and phrases that help or hinder the inbox position is to use a forensic tool – like e-shot forensics – where you can benchmark and analyse your mails so you aren’t sending blind.

With forensics you can review these element before your send your message out into the big wide world. With the insights you can get from your email Forensics you can review the key elements of deliverability, content and infrastructure when sending Test emails, so you can be confident your email will hit the mark before you hit send. The new reporting is fully integrated with the e-shot platform, so you can see all the information you need in one place. Within Forensics you can review any potential content or infrastructure issues, with the dashboard highlighting any areas requiring attention or with scope for improvement.

With our added Forensics insights you can test your email and understand your deliverability at the click of a button so you can continually optimise your campaigns, and improve your results.

Powered by Send Forensics the first class intelligence could be the difference between a successful campaign and an outstanding campaign – so speak to your account manager today, drop us an email at or call us on +44(0)20 3320 8777 and speak to us about adding Forensics to your email optimisation armoury.

Watch our webinar

There are many technical elements to making sure your email marketing gets delivered, but the most important aspects of good deliverability relate to your data and your content. Learn about the five things you should be doing to keep your emails out of junk in our dedicated webinar.   

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