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What is Email Deliverability? Plus 8 Ways to Improve It

Boosting your email deliverability is one of the quickest ways to get better results from cold emailing and email marketing.

Once you understand the factors that affect deliverability and the simple levers you can pull to improve it, higher open rates and stronger lead generation are just around the bend.

In this blog, we’ll demystify email deliverability and share easy-to-use tactics such as getting authenticated and keeping a clean email list.

Your journey to reaching more buyers starts here! 👇

What is email deliverability?

Email deliverability is the rate at which your emails land successfully in your recipients’ primary inboxes (not spam or social folders). It’s typically measured as a percentage of emails accepted by the ISP (Internet Service Provider).

If you have a high email deliverability score, your emails regularly reach your customers and leads, and few are blocked by your ISP or redirected to spam. 

To illustrate, if you have a 95% email deliverability rate and 100 recipients, five people will never see your email, but 95 will!

High deliverability is vital for the success of your cold emailing and email marketing campaigns. You need your leads to see your emails if they’re going to open and act on them.

On the other hand, low email deliverability means many of your emails are bouncing. You’ll want to fix this quickly, as it wastes money and time significantly. No one wants to craft and personalise an email only to have it end up in the spam folder.

What is a good email deliverability rate?

100% email deliverability is something to strive for, but it’s rarely possible.

A good delivery rate for mass email is 90-95% or higher for verified emails. Especially in B2B sales and marketing, where you send most of your emails to potential prospects you’ve never spoken with before.

The bounce rate should be below 3%, categorised into hard and soft bounces, and the spam rate should not exceed 0.08%.

That said, what is considered “good” differs between campaign types. For example, a cold email campaign will likely see lower deliverability than a campaign for current customers who opted-in for your email newsletter.

Consider this when evaluating your performance and deciding whether to celebrate or focus on fixing email deliverability.

What affects cold email deliverability? 

Many factors impact email deliverability, from your reputation as a sender to technical issues on the recipient side of things.

Knowing them will help you avoid the bad habits that hurt deliverability and pursue the ones that improve it.

Let’s review the most significant factors affecting your deliverability score 👇

Sender reputation

Your email domain reputation, AKA sender reputation, measures the health of your company’s domain. It’s based on factors such as the number of spam complaints, bounces, and unsubscribes you receive. 

It’s essential to monitoring this data. Why? You’ll maintain a good standing with ISPs, so they’ll accept your emails into their systems.

ISPs use their filters to decide whether to accept your emails. They’ll look for spam keywords, your email domain reputation and the content of your emails. 

To stay on the good side of these filters, avoid spammy words and phrases, be cognisant of the images you use and keep the content relevant and informative.

Email open rates

Email open rates directly affect your IP reputation. ESPs take low rates as a sign that your emails might be spam. Generally, you want an open rate above 20% - the average email open rate is around 21.5%

Note that buying pre-made lists often leads to low open rates. To avoid penalisation, you can invest in software like Cognism, which offers verified email addresses, list cleaning and data enrichment. 

Plandek is one company that has used Cognism to improve data quality and enrichment. This has resulted in a 95% email deliverability rate and a 52% increase in conversion rates! 

Discover how you can do the same 👇

Improve your email deliverability rate by 95% with Cognism.

Volume of emails

When preparing a bulk email campaign, you’ll want to hit “send” as quickly as possible. 

However, it’s important to remember that Internet Service Providers can interpret a sudden spike in your email send volume as a sign of spam or a stolen email address. This can lead to your emails being blocked and even suspended.

To avoid this, it’s recommended to spread your email volumes out over a period of time. This ensures that your emails are more likely to be delivered and reach the intended recipients.

Getting marked as spam

If several of your email recipients report them as spam, it will negatively impact your email deliverability. The ISP will start placing your emails in the spam folder; this is a sign of a lowered reputation with the ISP. It reduces the chances of your emails reaching their intended recipient, thus decreasing overall deliverability.

The best way to avoid this?

Send relevant and engaging emails to your audience!

Email content also plays a role in email deliverability. If your emails contain too many images, links, or promotional language, they might be flagged as spammy and automatically placed in the junk folder.

Be mindful of how you craft your messages and what words or phrases you use. Also, always include an unsubscribe link to allow people to opt out of your emails.

You should also consider using email deliverability testing software like Mailgun, which helps you check for potential issues before sending your emails.

Poor-quality email lists

Keeping an eye on your email list health is a surefire way to ensure deliverability. Regularly monitor your B2B lead list to identify inactive contacts, as well as any emails that have been marked as spam or have bounced.

Email tools like Cognism make it easy to clean email lists and lower bounce rates; by removing these stale entries from your database, you can keep it clean, making it easier for ISPs to deliver your emails.

Recipient-side technical issues

Sometimes, a technical problem on the side of your customer impacts email deliverability problems. Outages and full inboxes are particular issues that can prevent emails from being delivered on time or at all.

When outages occur due to a technical malfunction or scheduled maintenance, emails don’t reach their destination.

If a recipient’s inbox is full, your email won’t be delivered until the recipient has cleared some space. This can happen if subscribers aren’t regularly using their accounts or have an automated filter that discards emails after a certain number of days.

How do you check your email deliverability score? 

You may want to see how changes to your email lists or email strategy affect your deliverability. 

Or you may have a hunch that your email deliverability is lower than expected. 

How do you monitor performance and test email deliverability? 

A few email deliverability solutions are available to help you measure and monitor your score.

The first tool is an email delivery report. This explains how many emails were sent, delivered, opened, and bounced. This report will also tell you if there are any errors or issues with the delivery of your emails. You can access this with your email provider admin account. 

The second tool is Sender Score, a reputation and email deliverability checker. Sender reputation is a huge factor for ESPs in determining whether your email will be accepted into a recipient’s inbox, so it’s a good proxy metric for monitoring email deliverability.

Other tips for email deliverability checks are: 

  • Dig into the clickthrough and open rates data (if you have email lead generation software with analytics functionality). Sudden drops indicate deliverability problems. 
  • Look at unsubscribes, bounce, spam, and complaint rates. Spikes in any of these might mean an issue with deliverability.  

8 tips to improve your email deliverability

We’ve identified eight ways to improve your email deliverability and rack up those open rates! 👇

1. Get authenticated

Ensuring your recipients’ inboxes recognise you is key to your sender reputation. The last thing you want is for someone else to be able to impersonate your sender address (also known as email spoofing).

How can you counteract this? You must enable the following three things:

  1. Sender Policy Framework (SPF) - an authentication method designed to identify forged email addresses during the delivery process.
  2. DomainKeys Identified Mail (DKIM) - another authentication method that enables the recipient to verify that an email was sent by the domain owner from which it came.
  3. DMARC: As of Feb. 2024, Gmail and Yahoo will start requiring DMARC for those sending over 5,000 emails daily to Gmail or Yahoo.

Taking these steps convinces the receiving ISP that your cold email is worthy of delivery. They prevent spoofing and, as a result, keep your delivery rates high.

ActiveCampaign’s verification tool allows you to check if your email addresses are authenticated. 

For more information on setting up or updating your SPF and DKIM, we recommend you contact your email provider.

2. Own an IP address

As your email marketing campaigns scale, you’ll need tools and processes to cope with the volume. 

Once your output reaches 25,000 emails daily, consider sending it to a dedicated IP address. This ensures that only your company’s emails are routed through (as opposed to a shared IP that hosts several senders), so the poor marketing of other campaigns won’t affect your email reputation.

You must “warm up” your IP address to build trust with the ISPs overseeing your mail delivery. Gradually increase the amount of mail you send daily to determine the IP as a legitimate sender. 

As ISPs consider email volume a determining factor in spam detection, it’s best practice to start small and work up to greater volumes to avoid being penalised.

3. Dodge spam traps

Spam traps are one of the main reasons why your cold email template hasn’t reached an inbox. Inbox providers commonly use them to catch harmful senders, though they can catch you if your data hygiene or sender practices aren’t up to scratch.

If a spam trap captures a sender, they are flagged and blacklisted, which is extremely difficult to reverse. 

The best ways to dodge them are by: 

  • Actively using a double opt-in process.
  • Validating new email addresses.
  • Managing your inactive subscribers.
  • Deactivating bounced email addresses.
  • Cleaning your lists and avoiding purchased email lists.

Note that premade lists you can purchase or rent often include spam trap email addresses, not to mention emails that people never gave their consent to use.  

4. Spice up your subject lines

The first thing your recipients see when your email arrives in their inbox is the subject line - and first impressions matter! It’s bad if your mail gets ignored, even worse if it’s marked as spam.

To ensure your readers are opening and engaging, keep your email subject lines catchy but free from spam phrases. Instead of using generic hooks such as “Free!” or “Click now”, write something that will stand out in a crowded inbox, offering real value to the reader. 

Here are our subject line top tips:

  • Pick out a key idea from the message you’re sending as your subject. Be honest - the subject line must accurately describe the content of your email.
  • Create a sense of urgency or curiosity. The language you use should draw people in and entice them to click.
  • Keep it short - studies have shown that subject lines with fewer than 50 characters are likely to perform best.
  • Always personalise your subject line, including the recipient’s name and/or their company name. Emails with personalised subject lines see an 82% increase in open rates.

5. Make your content shine

Once your emails are delivered to your subscribers’ inboxes, the next step is to get them to open and read the messages you’ve painstakingly crafted. This is where your content needs to shine. 

Emails must be readable and offer value, encouraging users to act. We’ve got some advice if you’re struggling to write a compelling marketing email:

  • Open your email with a question - this helps to create rapport with the reader.
  • Use formatting effectively. Don’t just type up long blocks of text. Capture attention by using bullet points, for example, to emphasise key points or messaging.
  • Utilise the active voice throughout your email to sound authoritative and involved. Words like “imagine” or “remember” suggest that you’re telling a story, while “because” is important in providing reasons why your reader might take action.
  • Always finish with a call to action demonstrating the benefits or the value you’re offering.

Watch this video to find out how to boost your email response rates, including real-life examples from our email outreach!


6. Optimise opt-ins

Those who have opted in will probably be active readers of your emails. Recipients who don’t expect or agree to receive your messages will either delete them without clicking through or mark them as spam. If the latter happens, it can be risky, leading ISPs to label all your mail as spam.

Optimising your opt-in process is a surefire way to improve your email deliverability. The best way to do this is to build in a double opt-in mechanism (such as a follow-up email to a sign-up form).

This simple step ensures that any user entering your database has explicitly consented to receive your communications. 

7. Ask for preferences

Keeping up with what your audience wants is one of the most important elements of email marketing. 

What’s the best way to discover how often your audience wants to hear from you and what they want to hear?

The answer is a preference centre!

It’s a form that gives users options other than simply unsubscribing. Potential options could be altering the frequency of their email sequences or changing the topics they want to engage with. 

It’s also possible for subscribers to change their personal details through the preference centre, avoiding the all-too-common problem of a list peppered with invalid email addresses.

8. Keep your email lists clean

Having invalid email addresses and inactive or disengaged users on your list can harm your delivery rates and, ultimately, your sender reputation.

Ideally, you only want to market to people actively interested in receiving your messages. List hygiene should be near the top of your marketing priorities; you should aim to clean your B2B lead lists at least twice a year. 

You can spot when it’s time to take action when your B2B marketing campaign analytics reveal a large drop in your open and click-through rates. Unsubscription, bounce, and spam complaint rates are indicators, too.

Increase email deliverability with Cognism

To ensure maximum email deliverability, you must pay attention to several factors. They include the size of your email lists, content quality, and technical issues on the recipient’s end. It’s also important to spread out email volumes and ensure that the content of your emails is not flagged as spammy by ISPs.

Investing in a tool like Cognism to clean and enrich your list can ensure your emails reach their intended recipients.

Cognism provides verified B2B email data that can dramatically improve your email deliverability, allowing you to reach and convert more leads. 

When Protolabs started using Cognism, their email campaigns consistently hit 95-98% deliverability - a massive boon for their prospecting efficiency!

Check out how Cognism can help you increase your deliverability. Click to book a demo 👇

Reach your ideal customers with Cognism's data - speak to a data expert today!


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