The only email deliverability guide you'll ever need

Master your email deliverability with this simple, yet thorough expert guide.


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If you’ve ever sent cold emails, chances are you have encountered issues like high bounce rates and low engagement. These are just a couple of the many signs that your emails either aren’t making it into your prospects' inboxes, or that that’s what’s about to happen.

Fear not, for this expert guide to cold email deliverability will cover everything you need to know to make sure your emails reach inboxes, get opened, and help you get more prospects taking action on your offer.

Let's cover the basics...

What is cold email deliverability, and why does it matter?

To put it simply, email deliverability is the measure of the number of emails you sent, versus the number of emails that actually went into an inbox, as opposed to a spam or junk folder.

This matters because if your emails aren’t making it into inboxes, they’re not being seen. And why would we keep spending time and money sending emails out that aren’t getting read? That’s right... we wouldn’t.

So how do we make sure your emails actually make it into inboxes so they have a fighting chance of being read? Keep reading!

“Email deliverability all boils down to your reputation as a sender”

which ESPs (email service providers) - think, Google, Yahoo, Microsoft, AOL, etc. - keep track of. Yep, I’m sorry to tell you that report cards didn’t end when school did. ESPs are observing your behavior as an email sender, and they’re watching the behavior of the recipients of your emails, which brings me to my next point.

Your email deliverability is measured in two main categories: Sender Behavior, and Recipient Engagement.

Let’s dive further into each category so you have an understanding of how to show ESPs that you’re a reputable sender.

Sending Behavior

One of the first things ESPs will look at is your sending behavior. Follow these five steps to show email service providers that you’re a reputable sender.

1. Buy Dummy Domains

Your main website has presumably existed for some amount of time, and you’ve probably sent emails from it with email addresses like This means that ESPs already have a report card on your main domain, which could be good or bad. In either case, we recommend buying different domains for your cold emails. This ensures that any bad history your domain has will not negatively affect your cold outreach, and it also ensures that if your cold outreach ever has a hiccup, it won’t jeopardize your main web domain.

To give you an example, our main web domain at Lucky Leads is, but we send our own cold emails from similar but different domains, like:,,, to name a few.

Be sure to only set up one email address per domain, and make sure those email addresses are personal addresses, like “”, not “”. Also make sure that when you send emails from this email address, the name in the email signature matches the name in your email address.

2. Configure Your Domains

Reputable organizations pay IT firms or in-house staff to ensure that their email infrastructure is airtight, and for good reasons. The measures they take prevent spammers sending emails from their email addresses, and help to avoid their emails from being intercepted and re-written before their intended recipients receive their emails. As you can imagine, large organizations exchange valuable information, and they don’t want hackers getting their hands on it or pretending to be them.

As a result of their precautionary measures, their domain configuration protocols have become the benchmark, the rule of thumb, or the precedent for proper email hygiene, which ESPs will measure your own email infrastructure against. Don’t worry, it’s free to configure your domains with a little learning, or, you can hire a freelancer on Upwork or Fiverr to help you for a low cost.

Here’s what you need to do - make sure you add SPF, DKIM, and DMARC records in the DNS panel for each domain you’ll be using to send your emails.

If you like getting a little technical and you want to set those up for yourself, here are some instructions to help get you there:




If you’d like to hire a freelancer, you can visit Upwork or Fiverr to look for an expert. Use keywords like “email deliverability” and “DNS records'' to help you in your search.

If you’d rather not be bothered with doing it yourself or looking for a freelancer, Lucky Leads can help you out. Just click here to set up a quick meeting and we’ll have you all set up in a matter of a couple days.

3. Obey Sending Limits

Each ESP has a maximum number of emails that you can send from your domain per day, and obeying these limits is crucial. In fact, we recommend staying well below them. ESPs observe your email sending behavior, and if you’re sending an inhuman number of emails per day (200+), your behavior looks abnormal - even if it’s within the limits. At Lucky Leads, we limited our daily sending volume to 150 emails per email address, and only 100 of those are cold emails. Here are a couple links so you can see what your ESP’s daily sending limits are:



4. Minimize Bounce Rates

A bounced email is an email that didn’t make it to the intended recipient’s inbox. Instead, their ESP returned an error message to your ESP. This can happen for many different reasons, but what’s important is that you minimize the number of emails that bounce, because a high bounce rate is a signal to your ESP that you’re likely sending bulk emails.

To minimize bounce rates, you’ll want to use a tool to validate all of the email addresses you plan to send emails to before sending emails to them. To do this, you can use a tool like Bulk Email Checker. All you have to do is upload a .CSV file, and in a short amount of time, you’ll know which emails to remove from your list, and which are good to send to. Make sure you only send emails to email addresses with a status of “Passed” or “Valid”, not “Unknown” or “Failed”.

5. Avoid Spammy and Repetitive Content

Last but not least, ESPs also look at the content of your emails; namely, your subject line and body copy. Over time, their technology has become very good at detecting emails that look like spam, and it's your job to make sure your emails don’t get labeled this way.

We’ve compiled a list of over 400 words and phrases that can trigger spam filters. We recommend avoiding these words entirely by finding another way to say what you want to say, but if there’s no way around that word or phrase, then pay attention to the context around the words. If it still sounds spammy, consider taking a different approach with your email.

Other content that can trigger spam filters includes photos, videos, and buttons. Avoid these if possible.

The other aspect of your content that ESPs will look at is repetitiveness. When they see that you’re sending out tens or hundreds of the same exact email every day for a prolonged period of time, they start to get the picture that you’re bulk emailing. You have two options to avoid this becoming an issue. The first is to write a custom first line for each of your emails, so that no two emails are exactly alike. But if you’re like us and that sounds like too much research and work, then be sure to refresh your copy every 2-3 months by writing a new email sequence.

Recipient Engagement

Email Service Providers not only look at your sending behavior, but they also look at how your email recipients are interacting with your emails. If interaction is low or negative, you will be marked a spam sender. If your emails receive lots of positive engagement, then you will benefit from a good reputation score as a sender.

Getting high engagement is the most important component of your email deliverability, and ESPs measure it in four ways: 

  • Open Rates: If your emails aren’t getting opened, then ESPs know something is up. Make sure to write a compelling subject line. You can read our article on crafting a killer subject line.
  • Reply Rates: If nobody is replying to your emails, then once again, ESPs know something is up. Your content needs to get your prospects to reply to you, or at the very least, get them to click, which leads me to my next point.
  • Click-through Rates: If your prospects aren’t clicking on the link(s) you’ve included in your email, then ESPs know your email is not relevant to your audience.
  • Spam Rates: If your prospects are manually marking your emails as spam, this is the kiss of death for your reputation.

In order to get high engagement and avoid being marked as spam, make sure that you’ve properly understood your audience, and written a message that provides value and calls them to action. To give you that extra boost with email engagement, be sure to put your newly created domains on an email warming service. 

Services like Warmup Inbox will send emails from your email addresses, and perform a number of activities on the recipient’s end to show ESPs that your emails are receiving high engagement. We suggest doing this for at least one month prior to sending any cold emails, and keeping it going while you are sending cold emails. Maintaining a ratio of 2 cold emails for every 1 warming email will help your emails reach inboxes instead of spam folders now and into the future.

Monitor Your Deliverability

Your email deliverability is an ongoing matter, and can change at any moment. As such, it’s important that you keep a close eye on it. You can measure your deliverability with tools like Glock Apps.

If your deliverability score ever drops below 80%, we recommend pausing all sending from that domain and keeping it on your email warming service until it reaches 90%. We also recommend changing your content.

Need help?

If you’re not sure how to craft your first email sequence, or you’ve tried your hand at creating one but it’s not getting the kind of response you were hoping for, our team of expert email copywriters is here to help. Just schedule a quick call with us so we can go over your needs and craft a cold email sequence for you that will engage your audience and inspire them to take action.

Be sure to download our Cold Email Deliverability Checklist, and if ever you need help making sure your campaign is set up for success, you can contact us anytime!

James Bazakos

Founder of Lucky Leads, Cold Email Expert

For the last three years, James has been crafting cold email campaigns to deliver results to his clients. He hopes this blog post will help others learn what he has in a shorter amount of time.

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