discuss project

The open and click-through rates of your emails are important metrics to keep track of when determining the overall success of your email marketing strategy. However, before those metrics can be collated and analysed, your emails first have to be delivered to the recipients’ mailboxes.

Deliverability can be affected by a number of factors that we’ll look at in greater detail, as well as what you can do to improve yours.

How do we Define Email Deliverability?

Simple definition: The ability to deliver emails to your subscribers’ inboxes.

In 2016, Gmail introduced a drastic change to how emails were delivered – nullifying the scatter-shot approach that multiple companies used.

Rather than sending out emails with a 100% delivery-rate to your entire subscriber list (even inactive accounts and those who hadn’t opened emails from your address in months), Gmail decided to place a much greater emphasis on engagement and quality. If your tactics didn’t meet their standards, your emails simply wouldn’t be delivered.

The quality of data that a business is able to collect will directly affect the deliverability of their emails, as it’s intrinsically linked with sender reputation.

Sender reputation is a score that an ISP assigns to an organisation that sends lots of emails. The higher the score, the more likely an ISP will deliver emails to the inboxes of recipients on their network and vice versa. Factors include:

  • The number of emails sent out
  • Complaint rate and spam rate
  • How often your emails hit the ISP’s spam trap
  • Email bounce rate as a result of unknown users (Unknown User Rate)
  • How often the emails are interacted with (open rate, replies & forwards, CTR, deletion rate)
  • Unsubscribe rate.

Calculating email deliverability is easy. Simply take the number of emails that reach your subscribers’ inboxes and divide it by the total number of emails sent; multiply that figure by 100 to get the email deliverability percentage.

Your goal should be to maintain an email deliverability rate as close to 100% as possible.

Improving Your Email Deliverability

1. Stick to a Consistent Schedule

Striking that all-important balance with sending frequency may take some trial and error at first, or perhaps some common sense depending on the type of organisation; that is to say, if you operate as a daily, weekly or monthly newsletter – your sending frequency should coincide with whichever precursor best describes your business.

Devise an experimental schedule to gauge your subscribers’ engagement levels. An example of this could be to send out one email in the first month, two in the second month and four in the third month, etc.

Act accordingly and adopt a posting schedule to whichever frequency showed the most promising results. It’s important to remember that fluctuation is likely to occur depending on factors such as day of the week, time and even month. This all must be taken into account when developing the most effective schedule.

2. Double Opt-In

Double opt-in – also known as confirmed opt-in – is a feature used to reaffirm the user’s decision to subscribe via an automatic confirmation email that’s sent after clicking the subscribe button.

The advantages of double opt-in are the following:

  • Lower bounce rates
  • Higher open rate
  • Higher quality leads
  • More engagement
  • Lower unsubscribe rates

Web browsers tend to avoid interacting with anything that appears tedious or involves one too many clicks. While a single opt-in procedure is likely to provide a big short-term boost to your subscriber count – owing to its simplicity and speed – it can adversely affect your deliverability rate in the long-term.

Users might forget, or not even realise, that they’ve signed up to your email list when a single opt-in or pre-checked box is involved. Users will either unsubscribe – which is fine, or trigger a spam complaint. The latter is to be avoided at all costs, as spam complaints directly impact your deliverability rate.

3. Simple Opt-Out

The CAN-SPAM Act mandates that organisations give their subscribers the opportunity to opt-out whenever they wish. Not only is it a legal requirement, but it’s also a good business practice that should be as simple as possible.

If a user no longer wants to receive emails from your organisation, let them unsubscribe. There are no benefits in complicating the process. If you think a user will simply give up and carry on as an unwilling subscriber – you’re wrong!

Guess what? If there’s no clear opt-out feature, all the user has to do is mark your emails as spam and voila! They’ll stop receiving your emails and, in return, you receive a spam complaint.

Avoid this scenario with a hassle-free, one-click unsubscribe function to part on good terms.

4. Clean Your Email List

Subscriber maintenance is an integral part of increasing your deliverability rate. Do this by taking a careful look through your list and purging accounts that are consistently bouncing or those that rarely – or never – engage with your content.

Actively decreasing your subscriber count will undoubtedly be a painful experience, but it’s important to keep in mind that these accounts are nothing more than false-positive stocking filler. Their extra numbers make your list appear healthy, but in reality, they aren’t serving any purpose.

List hygiene should take place at least twice a year. Six months should give you a good idea of who is or isn’t regularly engaging and will allow you to segment your list and conduct a re-engagement campaign on those who aren’t fully considered to be lost causes.

Wrap Up

If your subscribers aren’t receiving your emails, how are they supposed to know about your promotions, products and content? Email deliverability can have a huge impact on the success of your various campaigns and the metric should be centre stage of your email marketing strategy.


Subscribe to
Incrify newsletter
Stay tuned for all the latest updates in the world of hi-tech


  • Updates on most innovative releases
  • Announcements of new products
  • Case studies of most successful projects
  • Notifications on most informative exhibitions and events
  • Discounts and promotions on valuable items
  • General useful information

Spelling error report

The following text will be sent to our editors: