definition backgroundMarketing qualified lead: All you need to know about MQL

Boom ! Now you’ll know how to ensure email deliverability with 6 simple steps

By Anna BenzaquenUpdated: February 8, 2023, first publication: November 2022

Email marketing can be a great way to grow a business of any size but just building a large mailing list isn’t enough. If your subscribers aren’t seeing your emails in their inboxes, your list is weakened.

What does email delivery refer to? Email deliverability is a performance indicator that marketers use to determine an email campaign’s health. We’re here to help you strengthen your operation.

What is email deliverability?

To put it simply, email deliverability is the ability to land your emails in the correct inboxes 🛬. This is not to be confused with your delivery rate which is the percentage of emails that arrive in your subscribers’ mailboxes but it still counts your subscribers’ spam folders as a successful delivery.

To understand deliverability, we first have to understand an email’s flight path which may not be as direct as you would think. There are three major players involved:

  • Sender
  • ISP
  • Receiver


You are the departure point for your email. You write your marketing content and hit send, launching it across the internet to hopefully land safely in your subscribers’ inboxes.


The ISP is the Internet Service Provider that controls whether your email reaches its destination safely or not. It scans content, filters spam, and sorts the emails according to its algorithms.

In order to send your emails to the proper locations, the ISP will run a sender reputation check to determine whether or not your email campaign is legitimate 👌. If you have good credibility, your email will be more likely to land in the correct inbox. If not, the ISP can send your message to the recipient’s spam folder or bounce (reject) the message entirely 😬.


When your subscribers receive your emails, they boost your sender credibility by opening and interacting with your emails. ISPs evaluate engagement to understand whether your emails are wanted or unwanted.

Email Service Providers may also factor into the email’s path by providing marketing and bulk email automation. ESPs will receive some information on why a bounced email was rejected.

Why deliverability should matter to you

It’s all well and good to understand that deliverability is different from delivery but why should you care?

Email marketing has a huge ROI for businesses when used correctly and strategically. You spend time and energy crafting your emails and marketing campaigns. All that goes to waste if your email doesn’t reach its intended destination. It benefits you to optimize inbox placement and opening rates.

However, you are not the only one with an email marketing campaign, so how do you stand out in your subscribers’ inboxes? Curate relevant and engaging content. This kind of content lets you kill two birds with one stone: you can build subscriber engagement with loyalty to your brand and you avoid spam filters.

6 steps to boost your deliverability land you safely in inboxes

After all that, how do you actually go about increasing your deliverability? These 6 steps will help your emails find their marks:

  • Choose the correct IP
  • Use a double opt-in process
  • Clean up your list
  • Write genuine subject lines
  • Sort your subscribers
  • Get the timing right

Choose the correct IP

The IP address that you choose will directly affect the path your emails take. You can choose from two types of IP addresses: shared or dedicated.

If you use a shared IP address, as the name suggests, your company will use the same IP as other companies which could affect your sender reputation. If you are a small sender, this could benefit you since you can cash in on other companies’ good reputations.

A dedicated IP address sends exclusively your emails, giving you unilateral control over your sender reputation. This option will probably be the most beneficial if you have a high-volume, high-frequency list.

Use a double opt-in process

If you use a double opt-in process, you are making sure that your subscribers:

  • Know what they are getting in to
  • Want to see your content
  • Are more likely to engage with your content and boost your reputation

Using a single check box or a hidden subscription method runs the risk of annoying subscribers and getting you sent to the spam folder, making ISPs more likely to sort you unfavorably.

On the other end, you can check in with low-engagement subscribers and give them the option to opt-out so they don’t clog up your list and drag down your sender reputation and deliverability.

Clean up your list

Keeping inactive subscribers on your mailing list may make it look nice but ultimately, they are just dead weight. Prune your list regularly so the active participants can thrive. Also make sure to give people a clear path to unsubscribe when they want. If the unsubscribing process is easy, it may, counter-intuitively, encourage them to resubscribe later on.

Write genuine subject lines

Your subject line is the first and sometimes the only thing your subscribers see of your email. Make sure it’s a good one. If you focus on your genuine message rather than selling, your subscribers are more likely to engage.

Subscribers aren’t the only ones reading your subject lines though. ISPs scan subject lines to check for spam and clickbait. Some phrases to avoid might include:

  • Free
  • Risk-free
  • Eliminate your debt
  • Go debt-free
  • Double your income
  • You are not alone

Sort your subscribers

Sending out bulk emails while you are still building your sender reputation can make ISPs think your campaign is spam. To avoid this, sort your subscribers and email them in batches.

You can sort them by:

  • Engagement level: send your emails first to your most engaged subscribers so you increase the chance of them opening your emails and boosting your credibility.
  • Engagement type: some subscribers respond well to content while others only respond to discounts and deals.
  • Demographics or location: if you sell multiple products.

Get the timing right

Email campaign timing is a balancing act ⚖️- if you send too many, you might get sent to the spam folder but if you don’t send enough, your subscribers might forget about you.

If you have enough marketing material, sending out promotional offers once a week might strike the right balance for you. You can do a trial to find the right frequency for your audience or you can set up subscriber preferences to take the guesswork out. Once you find your frequency, try to stick to a schedule since sending spikes can cause ISPs to distrust you.

3 things that will crash land you in spam folders

While you find the right balance on your email campaign to-do list, make sure you don’t forget the to-don’t list. These three things are almost guaranteed to get you on an ISPs bad side:

  • Using non-permission-based lists
  • Embedding or attaching forms
  • Including videos or JavaScript

Using non-permission-based lists

Whatever you do, DO NOT buy or rent lists. First, this will usually go against the terms and conditions of your ESP. Second, receivers who don’t recognize your brand are far more likely to either dump you in their spam folder or immediately unsubscribe, both of which will hurt your credibility and deliverability.

Non-curated email lists also often include invalid email addresses that will bounce your emails straight away. They may also include spam traps- email addresses set up by the ISP to catch spammers. If you end up in this trap, the ISP will put you on a deny list and it’s almost impossible to get off this list.

Embedding forms or attaching files

ISPs can flag embedded forms or attached files as security risks. Instead, you can include a link or a button that will take the subscriber to your landing page.

Including videos or JavaScript

Most email clients don’t function with dynamic scripts or videos so, even if you avoid the spam filter, your subscribers likely won’t be able to view your email. You can include an image from the video with a link to an external platform.

To conclude

With the enormous number of emails being sent around the world every minute, it’s easy for your email marketing campaign to get lost in the crowd. Small, innocuous mistakes can hurt your ROI and your business in the long run. You are investing time, effort, and money into your email marketing campaign. With a few judicious adjustments and an eagle-eye watching out for pitfalls, you can increase your sender reputation, your customer engagement, and your ROI. Now, go forth and conquer those inboxes!

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