Email Deliverability: how to prevent emails landing in the “junk” folder?

How to prevent emails landing in the “junk” folder?

If you want your email to be sent in the inbox instead of the junk folder or to be considered as spam, we recommend you to comply in three steps:

  • Reputation
  • Infrastructure
  • Authentication (optional)


First, let’s define the three terms:

  • Reputation: this term means your own server, that is to say your IP address and your domain name.
  • Infrastructure: this term refers to your servers’ infrastructure or system design.
  • Authentication: this term allows you to verify, or to validate, an identity in an electronic exchange to control access to a network or a software.



Your reputation is based on your standard score. You have to make sure that it always fluctuates and stays close to 100. Getting caught with spam traps will make you fall to 0 rather immediately. As a general rule of thumbs, your emails must be properly formatted, it means that it cannot contain only pictures (high ratio of image to text content) and your keywords used must be filtered against spamming phrases such as “click here” or “free”. Furthermore, the email sending trend shall be consistent by spreading sending quantity over time rather than sending a very high volume of emails within a day in a month. Lastly, your email database has to be clean to reduce bounce rate as much as you can.



We categorized it into three main components:

  • Web (Software Application): this is the email marketing software application you’re using every day. The application must be securely hosted to avoid potential hacking and data leakage.
  • Database: the database system is the system that records all the activities run by the software. Database system together with application hosting should be well-planned to increase the efficiency of sending.
  • MTA (Mail Transfer Agent): this is the email servers which push out the email messages. In our case, we are using multiple dedicated IP address to increase inbox placement rate.



The authentication will help you understand who the email sender is. There are two main methods of authentication:

  • DKIM > Domain Keys Identified Mail
  • SPF > Sender Policy Framework

Together, they form the DNS, the Domain Name Server. In brief, with this addition to your DNS entries, you’re telling recipients that you’ve authorized your email marketing service provider to send emails on your behalf. Without this change, your email has a higher chance of being marked as spam since the email was addressed from your domain but was sent from an IP address with your email marketing service provider’s domain.

You may think “okay, but what’s the relationship between all of them?”

Well, despite the authentication being optional, if you don’t monitor both your IP reputation or build a proper email marketing infrastructure, you might encounter major email deliverability issues, which would eventually get you a low response rate because a lot of your emails go to spam mailbox; and worst case is that your sent emails fail to arrive or blocked.


If you would like to learn how Wave Evolution can help you with email deliverability, please email or visit