What is E-mail Deliverability and why should I take it seriously?


E-mail Deliverability is the delivery of e-mails to the inbox of your recipients e-mail client. Problems in deliverability arise when e-mails don’t make it to the inbox. This can be, because they were placed in the spam folder or didn’t make it to the final recipient due to blocks.

Why are some e-mails delivered and others not?

The delivery of e-mails from the moment you send a campaign to the point where it reaches the inbox of it’s final recipient passes many obstacles (check out Litmus very helpful infographic to learn about the details: https://litmus.com/blog/why-e-mail-designs-break-rendering-guide-infographic/litmus-road-to-rendering-infographic).

The potential blocks and filters on its way that determine whether your e-mail reaches the inbox or doesn’t are mainly based on three columns:

  • IP Reputation The IPs from which you send your messages (every e-mail server that sends messages uses IPs such as 54.240.8.18

  • Domain Reputation The sender from domain that is used when sending your message, like newsletter@yourcompany.com

  • Content The content, such as text in the e-mail and subject line, images and html/css code that you send

How to build a good reputation

How content filters work is easy to imagine. Content that meets certain criteria, contains words from adult content or other elements often used in spam messages triggers a spam score and improves the likelihood of the messages landing in the spam folder or being blocked completely.

IP and Domain Reputation are more important though and more complex. The reputation your sender domain and IPs have with ISPs such as Gmail, Hotmail, Yahoo and others is similar to a credit score and largely based on behavior in the past. The reputation is evaluated by metrics such as: How many of the e-mails you send are opened or clicked on vs. how many e-mails are marked as spam or unsubscribed from (how high is engagement with your e-mail broadcasts). How many of the e-mails you sent to are invalid or temporarily unavailable (they are called hard bounces or soft bounces).

To summarize, you get the highest scores for reputation if engagement with your e-mails is high.

The score for reputation is often given to the IPs and sender from domains you use, who often are shared with other senders on platforms such as Mailchimp, Campaign Monitor or Aweber. So reputation is shared with other senders like you. But these platforms are quick to penalize bad sending practices and close your account or send your messages from lower quality sender domains and ips in case you are bad for their reputation. For the purposes of this article we didn’t go into the technical specifics of how sender systems are set up. If you want to know how to build your own reputation or improve your deliverability, get in touch @mailer_bob.

Why should I care?

A good reputation with ISPs is ultimately what will get you into the inbox of your recipients. If ISPs such as Gmail and co. register that there is a high interest of their users in your messages they will ensure it reaches their inbox and gets their attention. If the opposite is the case and they notice that your e-mails are never read, never clicked on unsubscribed from or even worse, marked as spam, your sender reputation drops and your messages are more likely to end up in spam folders or get blocked.

So send engaging e-mails to recipients that want to receive it.

Interested in knowing more or still have questions? Get in touch @mailer_bob