Email Delivery Rate 101: Definition and calculation methods

‍Email delivery rate matters. It's the percentage of emails that make it to your recipients' servers, not their inboxes: just their servers. Calculating it is simple, yes, but also extremely important for your campaigns' success. 

In this guide, we'll break down the steps to calculate your delivery rate, what factors impact it, and how to improve it. No fluff, just straight answers. And when you're ready, Mailreach's email warmup service and Free Email Spam Test are here to ensure your emails hit inboxes, not spam folders. Want more details? Let’s go.

What is email delivery rate compared to email deliverability rate?

Email delivery rate and email deliverability rate aren't the same, and mixing them up could cost you. 

Delivery rate measures the percentage of emails that reach the recipient's server, but doesn’t matter if they land in the inbox, spam, or promotions tab. It’s mostly influenced by bounce rates, which are tied to factors like email list quality and sender reputation. So, you could have a high delivery rate and still end up in spam: bad news for your campaigns!

Deliverability is about reaching the actual inbox. It’s the metric that really counts because it directly affects engagement and conversions. The catch? The best you can do is run consistent spam tests to get a solid sense of how your campaigns are performing. 

Bottom line: focus on deliverability if you want results, but keep an eye on delivery as a baseline check.

Why is email delivery rate important?

A solid email delivery rate is non-negotiable for successful campaigns. If your delivery rate is low, it’s a red flag that your bounce rate is too high, which points to poor email list hygiene. High bounce rates do more than just block your emails: they damage your sender reputation, making it even harder to reach your audience next time.

Good email deliverability rates start with a strong delivery rate. Think of it as your first line of defense, meaning that if your emails don’t even reach the server, they have zero chance of landing in the inbox. 

Our tip: Aim to keep your delivery rate above 95% to protect your sender reputation and ensure your email list stays healthy!

How to calculate email delivery rate ?

To calculate your email delivery rate, use this formula:

Email Delivery Rate = [(Total Emails Sent - Bounced Emails) / Total Emails Sent] x 100

For example, if you send 1,000 emails and 50 of them bounce, your delivery rate would be 95%. 

The key here is to minimize bounces, because a high bounce rate doesn’t just lower your delivery rate; it also damages your sender reputation. Also remember to regularly clean your email list to boost your delivery rate and keep your campaigns on track.

What is a good average email delivery rate?

A solid email delivery rate sits between 95% and 99%. If you’re hitting these numbers, it means your email list is clean, your content is optimized for inbox placement, and your relationship with email service providers is strong. 

It’s a clear sign that your emails are reaching your audience as intended!

What is a bad average email delivery rate?

Anything below 85% is a major warning sign. It indicates issues like outdated or poor-quality email lists, a damaged sender reputation, or email content that’s getting flagged by spam filters. 

So your rate drops this low, you need to act fast to fix the problem before it derails your entire campaign. Or you will regret it sooner or later.

Factors that affect email delivery rate

The fewer bounces you get, the better your email delivery rate. Keep in mind that a bounce happens when an email fails to reach the recipient’s server, and it comes in two forms: soft and hard bounces : 

• A soft bounce is temporary. It might be due to a full inbox or a server issue, meaning the email could still get delivered later;
• But a hard bounce is permanent. It is usually caused by an invalid email address or a non-existent domain. These are much worse for your delivery rate and sender reputation. Way much worse. 

If you wonder what are the key factors influencing your bounce rate, here is what you need to focus on: 

• the quality of your email list (keeping it clean and updated), 
• the reputation of your sending IP, 
• your email authentication protocols.

The quality of your email list

The quality of your email list is the main thing to focus on (only if you want to maintain a strong delivery rate of course). 

If your list is filled with invalid or outdated email addresses, you’ll face a surge in hard bounces with undeliverable emails that come back with a "this address doesn’t exist" message. But stay aware, because hard bounces aren’t just minor setbacks, they directly lower your delivery rate and harm your sender reputation.

In simple terms: each bounce signals to email service providers that you’re not maintaining a clean list, which can lead them to flag your future emails as spam or block them altogether. Here are a few tips to avoid this:

• regularly clean your email list, 
• remove inactive or incorrect addresses, 
• and use email validation tools to ensure you’re only sending to real, engaged recipients!

Your sender reputation

Your sender reputation is the backbone of your email deliverability. It’s as simple as that. 

It’s what email service providers use to decide if your messages are trustworthy. How? Your sender reputation is built on your engagement rates: the more recipients open, click, and interact positively with your emails, the stronger your sender reputation becomes. 

On the flip side, negative interactions like high bounce rates or spam complaints can quickly damage it.

This is why minimizing your bounce rate is fundamental: every hard bounce signals to email providers that your list isn’t well-maintained, which is dragging down your reputation. The better your reputation, the higher the chances your emails will land in the inbox rather than being filtered out. 

For a deeper dive into managing and boosting your sender reputation, check out this guide: 7 ways to Improve Email Sender Reputation in 2024

Your email authentication methods

SPF, DKIM, and DMARC aren’t just acronyms, they’re essential if you want your emails to actually reach inboxes instead of rotting in spam. These protocols are your first line of defense, proving to email providers that your messages are legit:

• SPF (Sender Policy Framework) checks that your emails come from an authorized server. Without it, your emails look like spammy knock-offs and get blocked fast;
• DKIM (DomainKeys Identified Mail) adds a digital signature to your emails, showing that your content hasn’t been tampered with. It’s like sealing a letter before it’s sent, proving it came straight from you;
• DMARC (Domain-based Message Authentication, Reporting, and Conformance) ties it all together by giving you control over what happens if SPF or DKIM fails. It tells email providers to either quarantine, reject, or accept messages that don’t pass the tests.

These methods boost your email delivery rate, yes, but they also protect your brand from phishing attacks and build trust with your audience, and this is their superpower. If you skip them, you’re basically inviting your emails to get trashed.

Set them up right from the start. Here’s your guide: SPF, DKIM, DMARC: How to Implement Them.

How to improve your email delivery rate ?

Authenticate your emails: SPF, DKIM, DMARC

You must know that SPF, DKIM, and DMARC are the bare minimum if you want your messages to reach your audience. As we explained it right before:

• SPF verifies that your emails come from your server, so no more fake senders pretending to be you;
• DKIM adds a digital signature to prove your emails aren’t tampered with during transit;
• DMARC pulls it all together by deciding what to do with messages that fail those checks, either block them, quarantine them, or let them through.

Skip these, and you're risking your sender reputation and your campaign’s success. Set them up right, get your emails into inboxes, and protect your brand from getting flagged as spam. Time to get serious about email security.

List cleaning best practices

‍Keeping your email list clean is non-negotiable if you want solid delivery rates. Our advice: remove as regularly as possible invalid addresses and ditch outdated contacts.

For example, use tools like Verifalia or Zerobounce to scrub your list automatically, so you’re only sending to real, active addresses. 

Regular list cleaning is the simplest way to boost your campaign performance, cut bounce rates, and keep your emails where they belong: in the inbox, not the spam folder. So don’t guess, and clean your list and stay efficient.

Increase your engagement rate

To get the best delivery and deliverability rates, you need a high sender reputation. This is quite logical. And that reputation hinges on your engagement rate: how often your recipients open, click, and interact with your emails.

If you're in the B2B space, start with an email warmup. This process gradually increases your email activity, building trust with email service providers and boosting your sender reputation before you dive into your campaigns.

For B2C or opt-in emails like newsletters, focus on creating content that drives clicks and opens. The more positive interactions you get, the stronger your sender reputation and the better your chances of landing in the inbox. Choosing the right email service provider (ESP) can make a huge difference here. We recommend Brevo, MailChimp, or Mailerlite for top-notch performance with opt-in emails.

The takeaway: high engagement rates equal high deliverability. Warm up your sender reputation, craft engaging content, and pick the right tools to maximize your reach.

Tools and services to monitor and improve email deliverability rate

If you’re serious about hitting the inbox, you need the right tools in your corner. Start with Mailreach’s email warmup service. It’s specifically designed to slowly ramp up your email activity, building your sender reputation step by step. This makes all the difference when you want your emails to skip the spam folder and land where they should (but choose wisely between automated vs manual email warmup).

Then there’s Mailreach’s Free Email Spam Test and Checker. It shows you exactly where your emails are going, whether they’re making it to the inbox or getting trapped in spam filters. It’s a quick way to catch problems before they mess up your results.

Bottom line: to nail your email deliverability rate, focus on warming up your sender reputation and tracking deliverability with tools that give you real answers. No guesswork, just proven strategies to get your emails where they belong.

Discover the best email warmup tool for a perfect deliverability