Email marketing has its share of skeptics, but with an ROI of up to 3,600 percent, it’s hard to imagine why. Our guess: some email haters might have an email deliverability problem.
Emails are only effective if they actually reach your target’s inbox. (I know–duh, right?)
Emails disappearing into the void? Don’t worry—we can fix that together.
Whether you’re in sales or marketing, low email deliverability can squash the results of your hard work. In this guide, we’ll show you everything you need about email deliverability so your stuff can land in the right inboxes and be seen by the right eyeballs.
This is the next level after email delivery, which only marks the technical delivery of your email. Delivery only tells us the server received the email, not where it placed it.
When email delivery fails, it’s called an email bounce. This can be either a soft bounce, a temporary issue like a full inbox or a server problem, or a hard bounce from a misspelled email address or a blocked domain.
Your first goal is email delivery; the ultimate goal is email deliverability. The latter is more nuanced and depends on your email content, volume, authentication, and sender reputation.
The good news? There are steps you can take to maximize your email deliverability powers.
You want as many emails as possible to land exactly where they’re supposed to. But what is a realistic expectation? Can every email land in your recipient’s inbox every single time?
The answer is no, but there are email deliverability benchmarks you can use to determine whether there’s room for improvement.
While there isn’t a one-size-fits-all email deliverability rate to aim for, Validity’s 2023 Email Deliverability Benchmark Report found that the average deliverability rate was 85 percent. Some six percent end up in spam, and nine percent go missing (meaning that the receiving mailbox provider deferred or blocked them).
In practice, one of every six emails never reaches the inbox. Klaviyo’s data shows that marketing emails generate between $0.10 and $3.45 in revenue per email recipient, so if 15 percent of your emails disappear in a void, your bottom line is worse off.
Also, consider that different email providers have different email deliverability benchmarks:
Finally, email deliverability numbers can vary quite significantly based on your industry. Real estate, media, and travel enjoy huge email deliverability rates at 94 percent or more, while finance, insurance, and telecoms barely hit 80 percent. Software and retail sit in the middle at 89 percent and 87 percent, respectively.
How does your business rank? If your email deliverability falls anywhere below 85 percent, there’s work for you to do (and the steps below will help you do it right).
What contributes to high email deliverability? Here are the eight key factors.
To send your emails, you’re using an IP address. This can be a dedicated IP address—meaning you’re its only user—or a shared IP address that other senders use along with you.
On a dedicated IP address, you’re the only one dictating its reputation. However, when sharing an IP address, your reputation as a sender depends directly on others. For example, if other senders use poor emailing practices like buying email lists or sending millions of emails, your reputation will plummet.
Just like a sturdy house would collapse if built on sand, your emails need a solid infrastructure and setup to shine.
That infrastructure includes authentication with standards like SPF, DKIM, and Domain-Based Message Authentication and setting up your DMARC records. This lets mail servers verify the source of your emails.
Short and simple: you need to own the domain you use as a sender. That means that free domain email addresses like Gmail, Hotmail, or Yahoo are terrible for any type of bulk or commercial email.
Owning your domain also means your recipients will recognize it when they see your email in their inbox and grow to expect it, which will result in more opens and fewer complaints.
Your subject line can raise red flags if written in all caps, with excessive punctuation, using language that indicates spam (free, click here, big sale), or with misleading elements like RE: or FWD: when they’re not replies or forwards.
In the email itself, too many images can be an issue, as can URL shorteners—a strategy spammers use to conceal, well, spammy links. You’ll also want to ensure a mobile-friendly design and formatting that’s easy on the eye.
Mailboxes rely on algorithms that monitor the volume of emails you send. Sending 1,000 emails per week and suddenly sending half a million in a day is a surefire way to end up in spam folder jail.
The best approach is always to work up to the volume and frequency you need, especially if you’re changing your email service provider (ESP), rebranding, moving to a different IP, or looking to run high-volume campaigns. (You’ll find tips on doing so later in this guide.)
How your audience behaves when receiving your email is a huge signal. If they open it, engage with it, and click on links inside it, it indicates trust that your messages are worth their spot in the inbox.
To cultivate an engaged list of recipients, use double opt-in (i.e., ask new subscribers to confirm their new subscription via email) in place of a single opt-in, and make the unsubscribe link clear and easy to spot. It’s also worth cleaning up your email list—aka removing subscribers who haven’t engaged in several months—around once every quarter.
A hard bounce means you’re emailing an address that doesn’t exist (as opposed to a soft bounce, which is just a temporary email server failure or error). The more your emails hard bounce, the more your deliverability suffers—another reason a double opt-in is worth it.
Another thing to be aware of is spam traps—email addresses providers use as literal traps to catch spammers by placing them in spots only reachable by email scraping tools. If you happen to email these spam traps, your emails will end up in spam. Imagine that!
Finally, your recipients can manually damage your deliverability. How? By flagging your emails as spam directly in their mailbox. This usually happens if they don’t recall signing up for your emails or not seeing the unsubscribe button.
Luckily, all it takes to protect yourself from spam complaints is a solid cold email strategy and a clean, well-maintained email list full of only engaged subscribers.
Email deliverability can’t be fixed overnight—but you can improve it with a holistic approach to email that will win you revenue for years to come. This involves your tech setup for emails, your cold email strategy, and compelling content.
Before improving your email deliverability, first check its current state. Many tools, both free and paid, are available to help you check your emails’ reputation, spam scores, domain health, and more.
How to complete this step:
Your infrastructure is how your email sending works in the background. There are technical standards in place that protect both you and your recipients from spam, data breaches, phishing, and other email security risks.
Meeting these standards is a must-have for email deliverability.
How to complete this step:
You need to configure and publish the below protocols within your DNS records. Your email service provider likely already has step-by-step instructions to help you set these up—check there first. Alternatively, work with your tech support staff to make sure these are in place:
Are you using a shared IP address or a dedicated IP that’s just yours?
A shared IP address means that other companies use the same IP address as you to send their emails. A dedicated IP address is exclusive to you and totally unique.
The difference? The sender's reputation with others using the same shared IP directly affects your deliverability.
How to complete this step:
First, check with your provider to learn the type of IP you’re using. If you’re not sure, it’s almost certainly a shared IP. Ask your provider about the quality of this IP pool.
Then consider the benefits and drawbacks of your options:
Part of your sender reputation is having a domain name with a world-reputable provider. Why? Because some providers tend to get blacklisted more.
This happens when there are, say, 100 other domain names sharing an IP address, and some of them get flagged as spam. That affects the rest.
A top-level domain provider is essential for any type of email, but particularly cold emails—that’s because they’re unexpected by default.
How to complete this step:
Your domain provider options are endless, but your best bets are GoDaddy or Squarespace Domains. That’s what Vaibhav Namburi, the founder of the cold email platform Smartlead, tells us from his extensive cold emailing experience.
If you’re not already using GoDaddy or Google Domains, you can migrate your domain over from your current provider—just follow their instructions.
A no-reply email address sounds like a solid way to manage your company’s busy inbox. But using it can be harmful: not only does it directly hurt your deliverability—many spam filters catch emails from no-reply addresses—it also hurts your subscriber’s experience.
They’re more likely to open and engage with an email that comes from a real person instead of a generic brand name. You want your emails to be a two-way communication channel.
How to complete this step:
Instead of a faceless, no-reply sender address, go with:
Are cold emails your go-to prospecting strategy or one you want to implement ASAP?
Be smart about how you execute your cold emails. They’re our favorite, but they admittedly never see the response rate of regular emails.
Because of that, sending cold emails from your main domain—say, close.com—can deplete its reputation. This will affect the deliverability of other emails, such as marketing, onboarding, and even internal communication.
The solution is to have a parallel domain name just for cold emails. That could be [CompanyName].com.
How to complete this step:
You need dedicated mailboxes when you’re ready to scale your cold emails. To ensure emails land where they should, it’s best to map those mailboxes to sending providers strategically.
Smartleads’ Vaibhav Namburi recommends Outlook, Gmail, and Zoho as your cold email-sending providers using a 40-40-20 strategy.
How to complete this step:
The 40-40-20 strategy means that if you have 10 mailboxes, four should be on Outlook, four on Gmail, and two on Zoho. Also, make sure to:
“Warming up” is a concept of programmatically sending emails within a high-reputation network of emails. It mimics natural conversations between individual mailboxes.
This way, you’ll convince mailboxes you’re a natural creator having normal conversations with people. This will improve your email reputation, and more of your cold emails will land in the main inbox rather than spam.
How to complete this step:
Use a mailbox warmup feature with a product like Smartlead. Here are some best practices to keep in mind when doing so:
Spintax (short for spinning syntax) is the practice of changing your email copy to make each email read differently. You’re basically using synonyms to create randomization in your cold emails as you scale them.
Why? Because the more cold emails you send, the more variance you want. If one email is marked as spam, spintaxing ensures other emails are different enough to still land in the primary inbox—and stay there.
How to complete this step:
This is another feature of Smartlead and many cold email software solutions, so make it a requirement if you’re on the market for one.
Alternatively, you can do this manually if you’re still in the early phases of cold emailing. Some ways to spintax your copy include varying between:
This is the hill we’re willing to die on. Following up is the key to any emailing success—cold emails included. But if your first cold email to a prospect ends up in spam, every email that follows will suffer the same destiny, which renders follow-ups useless.
But if your first email lands in your lead’s inbox, the others that follow trail through perfectly fine.
That’s why you need a strategy behind each cold email you send to a prospect.
How to complete this step:
Feel free to use one of our cold email templates if you’re stuck on what to write.
The best email lists are packed with recipients who want to receive your emails, but not just that: they open them regularly, engage with them, and stay subscribed afterward.
Straight-up deleting subscribers who don’t fit that description might initially seem counterintuitive —why would you want to email fewer people than you could?
Because it drives email deliverability. Those who ignore your emails will never buy from you anyway, and deleting them means that more of those who want to buy will actually see your emails.
How to complete this step:
Once your email list is clean, how do you keep it that way? With the help of double opt-in. It’s a process of asking new subscribers to confirm their subscriptions by clicking a link you’ve sent to their inbox.
The alternative is adding literally any email address from your signup form to your email list, which can include dozens or even hundreds of spam addresses and bots. You might not spot them before it’s too late, and your deliverability has already crashed.
How to complete this step:
Each email provider sets a technical limit on the number of emails you can send per day, hour, minute, or a combo of those. For example, Google Workspace has a daily limit of 2,000, Gmail sending limits sit at 500 per day, while Yahoo! only allows you to send 500 emails per day and no more than 100 per hour.
If you exceed sending limits, you might see exceptionally poor deliverability or have your account blocked.
If you’re planning a larger outreach campaign or want to scale up your efforts in the long run, pay particular attention to your provider's limits.
How to complete this step:
Onboarding a new subscriber is a fancy way of saying: welcome them to this new email experience they signed up for. It won’t just serve as a reminder of what it is you do; it’s also a great way to earn their trust and kick off a relationship.
You can send a single welcome email or a sequence of up to three emails that introduce your brand and share your best content.
Without a welcome experience, they might forget they’d signed up by the time your next email goes out a week or two later—and mark your email as spam. 🤦♀️
How to complete this step:
Imagine receiving a daily email from a company you really like and realizing that daily is a bit much, but you’d love a weekly roundup… But there’s no option to tweak that.
Maybe I can reduce the number of topics I’m interested in, so the emails won’t arrive as often, you think. But that also doesn’t work.
You realize the only way to keep your inbox sanity is to unsubscribe—but that isn’t an option you can find either.
The only solution you have? Mark as spam and block forever.
By giving your subscribers an easy way to set their email preferences, you skip this scenario altogether and give them power and control over what lands in their inbox.
How to complete this step:
Email personalization means your recipients feel like the email was written for them.
Not just because they’re about a topic they’re generally interested in but also because it addresses them by name, gets specific about their pain points, or even includes their previous behavior like purchases.
This drives engagement and satisfaction—and what better way to show mailboxes your emails deserve their spot in them than that?
How to complete this step:
Personalization looks different for cold emails than it does for newsletters and marketing emails. Here’s how:
Predictable schedules are loved both by users and machines.
For users, it means they’ll learn to expect, open, and engage with emails when they land on the same day and at a similar time every time. For machines—internet service providers and mailboxes—it means a predictable, safe way to deliver a high volume of emails.
A sudden schedule switch, like going from one weekly email to five, will raise some flags with providers and likely annoy users—both possibly harmful to your deliverability.
How to complete this step:
Subject lines play two roles in email deliverability:
You’ve gone through all the hard work already—your infrastructure is perfect, your mailboxes are warmed up, and your email list is packed with excited subscribers and prospects. Don’t waste it by choosing any subject line that comes to mind.
How to complete this step:
Building and improving your email deliverability can turn into quite a project—and one that’s never really completed. It’s an ongoing effort.
The easiest way to start? Find the spots where you can make the biggest improvement. For example…
If you’re not on top of your domain reputation and email protocols, start with your domain providers and ESP settings to make them immaculate.
If your cold emails aren’t getting the desired results, find a product that will help you set up your parallel domain, mailboxes, warmups, and cold email sequences.
If your email list has been stale, give it a good spring cleaning and remove cold and bounced subscribers.
Write every email and subject line with the goal of making them irresistible—personalize them and tweak your subject lines as best you can to perfection.
Finally, bring all your sales conversations together in one ultimate place, like Close CRM. Track cold email open rates, interactions with leads, and conversions—results you created because your emails landed exactly where they were supposed to.