Email Deliverability Guide 2026: All You Need to Know

Email deliverability is one of the essential terms you will come across as an email marketer or cold emailer.

In simple terms, it is basically how likely the emails you send will land right in your recipients’ inboxes.

• High email deliverability → More emails reaching the Primary inbox
• Low email deliverability → Fewer emails in the Primary inbox

In this blog, I will share all you need to know about email deliverability in 2026.

Read on if you want more of your emails to consistently land in the Primary inbox this year.

What is Email Deliverability?

The textbook definition of email deliverability is:

Email deliverability is the ability of your sent emails to land in the Primary Inbox of your recipients.

Here is an example:
If you send 100 emails and 90 of them made it into the primary inbox, then you have 90% email deliverability

Email deliverability is also called inbox placement.

Email Deliverability and Email Delivery

A common point of confusion in email marketing and cold emailing is the difference between email delivery and email deliverability.

Both sound the same, but there is a slight difference

• Email Delivery refers to whether your email is successfully accepted by the recipient’s mail server.
  Once accepted, the email is considered delivered, regardless of where it lands (Spam, Promotions, Updates, Primary inbox, etc).
• Email Deliverability (inbox placement) specifically refers to your emails making it to the Primary Inbox tab.

In simple terms, delivery answers whether the email arrives, while deliverability answers where it ends up.

Without delivery, deliverability cannot exist.

At this point, you may ask, “Shouldn’t I be concerned about delivery first than deliverability?”

Both delivery and deliverability are influenced by a lot of common factors.

This is why serious email marketers and cold emailers always take an email deliverability-first approach.

In the next section, I will share some of the important factors that affect email deliverability in 2026.

Various Factors That Affect Email Deliverability in 2026

In this section, I’ll share 7 factors that have the greatest impact on your email deliverability rate:

1. Spam Complaints
2. Bounce Rates
3. Spammy Language and Phrases
4. Suspicious Email-Sending Patterns
5. Too Many Images, Links, and Attachments
6. Shared IP Addresses
7. Poor Sender Reputation

1. Spam Complaints

Spam complaints are the #1 factor that can make or break your email deliverability.

This will drastically lower your email deliverability, as your ESP will assume your account is an untrustworthy sender.

For example:
If you’re sending irrelevant emails to your prospects, they’re very likely to mark them as spam.

This is a direct feedback to email service providers that you are sending unwated emails.

2. Bounce Rates

If you’ve ever made a small error while typing your recipient’s email address or used an unverified email, you might have received a delivery report error: your message could not be delivered.

This is what we call a bounced email. And the number of emails that result in such errors makes up your email bounce rate.

There are two types of email bounces:

• Hard bounces
• Soft bounces.

Hard bounces occur when your recipient’s email address is invalid or incorrect.

This means the email cannot be delivered at all. This has the most negative impact on email deliverability!

On the other hand, a soft bounce can occur because of several reasons: your recipient’s ESP server is down, or their mailbox is full.

3. Spammy Language and Phrases

What do almost all malicious email senders have in common? 

They all use spammy words like “Once in a lifetime opportunity,” “You’re a winner!” and “Get rich quick…”

So, if you’re using such spammy phrases in your sales and marketing emails, ESPs might flag your email account as suspicious. 

And this will have a negative impact on your email deliverability!

4. Suspicious Email-Sending Patterns

The last thing that I’ve often noticed, which results in poor email deliverability, is an irregular email sending pattern.

For instance, if you send 1,000 emails today in the morning and by afternoon you are sending 1,000 more, you might alert your ESP!

It might think that you’re engaging in suspicious behavior and send your emails to spam.

5. Too Many Images, Links, and Attachments

Many fraudulent emails include links that take you to third-party websites that might harm your financial well-being. 

For this reason, you might have noticed that many of the emails in your spam folder contain too many attachments, images, or links.

Similarly, if you’re sending emails to prospects with many proposals, PowerPoint presentations, or links to your website, the ESP might route them straight to the spam folder!

6. Shared IP Addresses

An IP Address is your window to the Internet: it’s a series of numbers through which your Internet Service Provider determines your identity.

If you’re using a shared IP address, it means that thousands of other internet users might also be using it to connect to the internet.

And if any of them are engaging in suspicious or malicious activity, your ESP might lower the IP reputation of the entire network of users!

So, even if you are not using the internet or your email account for malicious purposes, it will negatively affect your email deliverability rate!

7. Poor Sender Reputation

Think of Sender reputation like the credit score of your email account: with a poor sender reputation, more and more of your emails will land in the spam box.

Sender reputation, much like email deliverability, is itself determined by your bounce rate, spam rate, and email authentication.

How to Build High Email Deliverability: Best Practices

Till now, we’ve examined in detail what not to do. 

Now it’s time to know how you can improve and maintain a high email deliverability rate.

1. Authenticate Your Email Account
2. Stick to ESP Daily Sending Limits
3. Use Double-Opt-In Subscriptions
4. Warm-Up Email Accounts
5. Never Use Spammy Language
6. Avoid Including Too Many Links or Attachments
7. Clean Your Email List
8. Send Personalized Emails
9. Switch to a Dedicated IP Address
10. Monitor Key Deliverability Metrics

1. Authenticate Your Email Account

Setting up these email protocols is very important to prove your identity to receiving mail servers →

• SPF: Sender Policy Framework 
• DKIM: Domain-Keys Identified Mail
• DMARC: Domain-based Message Authentication, Reporting and Conformance

2. Stick to ESP Daily Sending Limits

As I have already mentioned, every ESP has a strict daily email-sending limit.

And if you bypass this limit, your email will likely not even be delivered, let alone land in the primary inbox.

To ensure that you retain a high email deliverability rate, I recommend strictly adhering to the ESP’s sending limits.

One solution to this problem is to create multiple secondary domains and distribute the email volume among them.

3. Use Double-Opt-In Subscriptions

Double opt-in is a simple yet powerful way to protect your email deliverability and stay legally compliant. 

So what is it? 

Well, it is a 2-step confirmation process where the prospects confirm in two stages: once by signing up, and again by confirming via email that you are emailing people who genuinely want to hear from you! 

This may sound like an extra step, but it can make a huge difference! 

4. Warm Up Email Accounts

One of the easiest ways to guarantee high email deliverability is to warm up your email account.

It is a strategic process where you gradually increase sending volume to engage in real conversations with email accounts that have a solid sender reputation.

5. Never Use Spammy Language

As we’ve seen, spammy language can drastically lower your chances of landing in recipients’ inboxes.

To avoid this, I recommend that you always double-check your copy for any potentially spammy phrasing. 

This is especially important if you’re planning to send cold emails: if even a single email in your sequence contains spammy words, it might mess up your entire campaign!

6. Avoid Including Too Many Links or Attachments

If you’re emailing a recipient for the first time, you should never include any links or attachments.

Trust me: I’ve seen several cases where even the most important of emails are routed to the spam folder just because they contained many links, attachments, or images.

7. Clean Your Email List

If you want to avoid hard bounces, you should always clean your email list before using it for cold email or outreach campaigns.

This is important if you’re buying email lists from data vendors. Often, such lists contain invalid or outdated email addresses, which might lead to hard bounces and, therefore, low deliverability.

I suggest that you use an email verification tool like NeverBounce to clean your email list. 

8. Send Personalized Emails

One of the best ways to ensure that you’re always landing in inboxes is to send personalized emails. This is due to several reasons: 

• Recipients are less likely to mark personalized emails as spam
• You will avoid triggering spam filters by positioning your email as a unique message rather than a generic one
• Personalized emails are likely to have a higher reply rate, which will lead to a higher sender reputation and high email deliverability

9. Switch to a Dedicated IP Address

First and foremost, you should switch to a dedicated IP address. It will give you complete control over your internet activities and ensure that you don’t face the negative consequences of someone else’s actions.

There are three ways you can get a dedicated IP address: 

• Through your current ISP
• Via a hosting network like Hostinger
• By requesting one from a VPN service like NordVPN

While getting a dedicated IP address might seem like an extra task, I highly recommend that you get one if you want to ensure good email deliverability!

10. Monitor Key Deliverability Metrics

One thing I’ve learned the hard way is that you can’t improve your email deliverability without constantly measuring it through numbers.

This is because ESP behavior is often unpredictable: a small change in its policy can lead your email deliverability to take a hit!

To track performance more effectively, it’s important to understand the core email deliverability metrics that signal inbox placement, reputation health, and engagement trends.

Monitor key metrics continuously to ensure that your email deliverability is always on track. 

These include:

• Spam Rate
• Bounce Rate
• Authentication Success Rate
• Inbox Placement Rate
• Open Rate

How Can You Measure Email Deliverability?

If you want to improve your email deliverability, the first thing you need to do is measure it accurately. 

Don’t worry: it’s neither challenging nor do you have to do it manually because there are several dedicated tools you can use to measure your email deliverability.

Let’s take a look at three such standout platforms:

1. Google Postmaster Tools
2. SenderScore
3. MX ToolBox

1. Google Postmaster Tools

Postmaster Tools is Google’s native, free-to-use platform through which you can analyze and visualize your email-sending patterns and metrics.

It allows you to easily measure the following:

• Email spam and spam complaint rate
• Bounce rate
• IP and sender reputation
• Delivery rate

Simply put, Google’s Postmaster Tools helps you understand not just your email deliverability rate but also all the metrics associated with it. 

2. SenderScore

One of my go-to tools for measuring email deliverability is SenderScore.

It offers a full suite of email deliverability tools that you can use to easily measure your email account’s

• sender reputation
• bounce rates
• and spam rates.

Plus, if you think you’re suffering from poor email deliverability, SenderScore will give you a list of benchmarks you can monitor to improve your sender reputation and deliverability in one go!

3. MX ToolBox

MX ToolBox is an easy-to-use tool for tackling one of the most critical elements of email deliverability: authentication.

Its primary function is to establish and verify your SPF, DKIM, and DMARC records.

It also enables you to protect your email infrastructure from phishing and spoofing attacks.

One of the most important reasons why I recommend MX ToolBox is that it provides several other key features, such as threat intelligence, inbox placement rate, and blocklist monitoring.

Also check out this detailed MXToolbox review for a closer look at its features.

Increase Your Email Deliverability and Never Miss the Inbox!

Email deliverability is the only thing that stands between you and a successful email outreach campaign.

By following all the best practices listed, you can easily improve your email deliverability.

Remember, if you want to see success with emails in 2026, take a deliverability-first approach to cold emailing or email marketing.

FAQs: Guide to Email Deliverability

1. How Do I Improve My Email Deliverability?

Here are the best ways to improve your email deliverability:

• Use an automated email warm-up tool
• Switch to a dedicated IP address
• Authenticate your email accounts
• Always send personalized emails
• Avoid sending emails with links, images, and attachments

2. What Is a Good Deliverability Rate for Emails?

As per the cold emailing experts, a good email deliverability rate is somewhere between 90 and 98%.

3. What Determines Email Deliverability?

There are five main factors that determine email deliverability:

• Email sending frequency and pattern
• Email authentication and infrastructure
• Email content (including links and attachments)
• The quality of your email list
• Spam complaints and requests

4. What Hurts Email Deliverability?

There are four major things that can hurt email deliverability:

• Violating the ESP’s sending limits
• Not authenticating your email account
• Sending emails with spammy words, images, attachments, and links
• Not personalizing your emails