For social media managers, email marketers, and even the common office worker, knowing what email deliverability is can be crucial. The success of an email marketing campaign relies heavily on the number of people reached and on the number of emails successfully sent.

what is email deliverability

So, what is email deliverability?

The deliverability of an email refers to the calculated chance for an electronic mail message to be successfully delivered to the recipient. An email’s deliverability is the percentage computed from dividing the number of emails sent that did not bounce back by the number of emails that were actually sent. For instance, a deliverability rate of 95% is high and may be considered a perfect rate.

There are four stages in the deliverability of an email. These are the Network Level, the Server Level, the Recipient PC Level, and finally the Recipient Level. These are the stages that an email will move through from the moment it is sent out until the moment it is actually received by the intended recipient.

Network Level

At the Network Level, the sender’s email service provider can integrate various technologies in screening the message to make sure the emails which are classified “good” can go out of the server and those that are “bad” will be filtered out. It is worth noting that even at this basic level, glitches can be encountered. There are many instances when even “good” emails get lost due to failed techniques applied by the service provider.

Server Level

Next comes the Server Level. Here, the main controller is the domain host. For example, emails hosted under Gmail are controlled by Google while those by Yahoo mail fall under Yahoo. When the email leaves the Network level, it moves on to the Server Level where it is screened once again. Most of the filters at this level are governed by the server administrator. If it is an office email (free, not hosted), then it will be the company’s service administrators who will control such screening techniques.

Recipient PC Level

Once an email has left the Server Level, it flows through to the Recipient PC level. This is where Spam filters do their work. It can depend on two things: the spam score of the sender’s email and the recipient’s mail client. If the recipient’s mail client has a strict spam filter and the sender has a high spam score, chances are the email will not make it to the inbox. Otherwise, the email moves forward to the last level.

Recipient Level

At the recipient level, the email has finally reached its destination. The sender’s email has made it to the inbox without getting filtered or landing on the Spam/Bulk folder. This is the final stage...and the most important stage of all in email delivery.

Knowing the above can help both senders and receivers understand the reasons behind unsent emails and those that bounce back. Such knowledge can aid in taking steps to avoid getting your emails filtered out at any of these levels, resulting to an increase of your deliverability percentage.


Kane Miller from Winning.Email

Kane has a background in computer engineering, but now focuses on creating new and interesting web services. His passion for improving his own email deliverability rates was the driving force behind the creation of Winning.Email.