Email deliverability is, simply put, the ability to deliver emails to the recipient’s inboxes. It is defined by the ratio between the number of emails sent out and the emails that actually make it to the recipient’s inbox. No matter how legitimate an email marketer you are, there are a host of things that you may not even be aware of that lower your email deliverability rates. With data privacy laws becoming more stringent and sophisticated email filters on the rise, it is paramount to know everything that could impact your deliverability capability.

Regulatory Framework

Before drafting emails, ensure that your emails comply with the regulatory and statutory requirements outlined for business and commercial senders. Every jurisdiction including the United States, Canada, and the European Union have regulations relating to email marketing that ensure your emails are legally deliverable. In the United States, the CAN-SPAM Act protects consumers from unwanted emails giving them the right to unsubscribe from an undesired email list. Under this act, your messages must contain:

  • A subject line related to the content of your email

  • Valid mailing address for your business

  • A clear way for recipients to opt-out from receiving future messages

Should consumers unsubscribe from your emails, you are required to honor their request within 10 days after which you should stop sending the emails. Complying with these laws protects your business from getting too many spam complaints. Besides the CAN-SPAM Act, various states in the US have separate regulations for sending commercial emails.

Email Delivery Process: Who is Involved

There are three parties involved: the sender, gateways, and recipients. The parties, specifically the senders and gateways, play a significant role in the deliverability process by ensuring emails get to inboxes.


  1. Legitimate email senders: these are businesses that have a legitimate reason to send emails including newsletters, transactional emails, and marketing emails. Most of the legitimate senders have high deliverability rates since they have a personalized relationship with their clients.

  2. Email certification providers: These providers help you in the email delivery process ensuring high deliverability rates from ISPs. They are companies that have developed strong relationships with ISPs and can vouch for you as a sender, helping you to bypass ISP filters. Email certification providers are essential in your email delivery process since they help you in email authentication, which labels you as a legitimate sender and gets you off the ISP’s blacklist.


Gateways consist of the ISPs that control the way your emails are delivered. ISPs act as the link between your email and their recipient. They include major internet service providers and minor providers who are based in certain regions. Major ISPs formulate and implement the laws to ensure that only the right content gets to recipients. Minor ISPs purchase versions of the algorithms and processes used by major ISPS to monitor emails within a given region. You should meet the minimum requirements based on the filters and monitoring reports.

Email Deliverability Problems

Achieving optimal deliverability rates with your email marketing technique is a challenging task for marketers. A drop in the open-and-click through rates, increase in bounce rates, or find out that you have been blocked, are the first red flag that you should look out for during your testing state. Common problems include email authentication, content, and design hence the need to conduct email deliverability testing in a bid to address and resolve the problems.

  • Authentication: Sender policy framework, email encryption, and digital signatures vouch for authenticity. Although dealing with authentication challenges is daunting, getting an email certification provider will help you address any email authentications required by ISPs.

  • Content and design: email content and design play a fundamental role in engaging your readers. The use of free email senders, URL shorteners, or overused subject lines will ruin your email deliverability. Engaging content and personalized design account for higher CTR, which sends a signal to ISPs that you are a legitimate sender.

Improving Email Deliverability

There are numerous technical issues including Domain Keys Identified Mails, Sender Policy Framework, and Transport Layer Security that affect your deliverability, which are mainly handled by your ISP. However, there are key steps you can undertake to maximize your deliverability.

Get Permission

Before you create an email, ensure you have permission to send marketing emails to avoid being marked as spam. To enhance deliverability and ensure you are not marked as spam; you should get permission offline by asking customers at the cash register if they want to get email updates from your store or bring a signup sheet to a local event.

You can leverage on your website or blog by placing a signup form on the welcome page for visitors to fill. Your ISP will automatically add the visitors’ addresses on your mailing list. If you do not have a website, you can use web forms hosted on your ISP’s list then share the link on your social network for people to join your mailing list.

Personal Whitelist Requests

Asking subscribers to add you to their address list improves your deliverability rates. When you are added to a subscriber’s mailing list, it sends a signal to the ISP that your subscriber trusts you and wants to receive emails from you.

Retain a Good Reputation

ISPs are on the lookout of how readers engage and interact with your content to determine if the emails will get to recipients’ inboxes. Maintaining a good reputation with your subscribers involves sending informational content that your readers will open once received rather than delete them unread, getting rid of outdated email addresses, and keeping a regular schedule for your emails.

Email Deliverability Testing Guide

With over 280 billion emails sent and received each day, it is likely that your subscribers will receive your emails and delete them before reading or the emails land into their junk and spam folders. The key issues of concern when commencing on a deliverability test is to optimize the deliverability rates, click-through rates, and open rates. Areas on concern include:

  1. The quality of links in your content

  2. Authentications of the sender domain

  3. Text to image ratio

  4. Quality of HTML

Email deliverability may be a major challenge for your email marketing campaign. Work on improving your personalization tactics and testing tools to ensure you reach your intended target audience without any hitches. Now is a perfect time to check out our guide on email deliverability testing for a game-changing experience.