What is Email Deliverability & How to Improve It

If you ever scratched your head saying, “Why are my emails not getting replies?” 

An expert would first suggest, “Did you check your email deliverability?” 

Email deliverability is the main factor responsible for your email landing where it was aimed – in the inbox!

(Not spam, not promotions; Inboxes!) 

So, if you don’t know about it yet, this is the right time!

In this blog, I’ll help you understand,

• How do top senders consistently hit  >95% inbox rates?
• How do you fix deliverability?
• What makes inboxes trust one sender and block another?
• Which metrics and laws truly matter in 2025?

Let’s start!

What Is Email Deliverability?

Email deliverability is the ability of an email to get delivered to the recipient’s primary inbox. 

Emails should pass ESP (Email Service Provider) filters without being marked as spam, promotions, or blacklisted to reach the inbox!

If everything looks good? Inbox.

If not? It could end up in spam, be flagged, or even get blocked entirely.

The good news? You control a big part of this.

How?

The ability can be increased or decreased based on the practices followed by the sender. 

• Follow best practices, and your emails will land in the inbox more often. 
• Ignore crucial aspects affecting your email deliverability and watch it drop in a matter of days!

Difference Between Email Delivery and Email Deliverability

The main difference between the two is the metric on which success is measured!

Let’s understand it with the image below. 

Why Email Deliverability Matters for Your Business

If your emails don’t land in the inbox, your campaign is already failing. 

Email deliverability measures whether your emails actually reach your recipient’s inbox (not spam, not promotions).

And it directly affects how many people open, read, and reply to your messages.

Poor email deliverability = lower results

• Emails are landing as spam or promotions.
• Fewer people see your emails.
• More spam complaints, more blocks.
• Higher risk of getting blacklisted
• Damaged sender reputation across all future campaigns 

On the other hand, 

Excellent email deliverability = more replies, more deals

• More emails land in primary inboxes
• Follow-ups actually get delivered
• Email platforms trust you more
• Higher sending limits
• More opens, replies, and ultimately – more deals closed 

Bottom line:

Great deliverability means more visibility, more replies, and more revenue. 

How Does Email Deliverability Work

Unlike popular belief, it starts way before you hit the send button. 

It’s a process that involves multiple steps to ensure your email actually lands in your recipient’s inbox, and not their spam folder. Here’s a simple walkthrough.

1. You Set Things Up 
2. You Build a Good Sending Reputation
3. You Send the Email
4. Email Providers Check Your Email Format
5. Your Email is Placed: (Inbox, Spam)
6. People React To Your Emails

1. You Set Things Up

Before sending any emails, you need a proper setup.

This includes setting up authentication protocols like SPF, DKIM, and DMARC, using a clean email list, and warming up your sending IP/domain. 

These steps lay the groundwork for good deliverability.

2. You Build a Good Sending Reputation

Email providers (like Gmail, Outlook, Yahoo) track your reputation based on how you send emails over time.

• Did you spam people by mistake?
• Did too many emails bounce recently?
• Did people mark you as spam?

This affects how email providers treat your next email. 

To become an ESP’s trusted sender, you must follow recommended sending patterns for at least a few months. 

3. You Send the Email

Now you hit “send,” but your job isn’t done yet.

Your email is on its way, but it must pass several checks before it reaches the inbox. (mentioned in the next points)

4. Email Providers Check Your Email Format

The email service providers scan your email to decide if it’s safe.

They check:

• The subject line
• The words you use
• Links or attachments
• Overall format

If something feels off, they flag your email as spam.

5. Your Email is Placed: (Inbox, Spam)

Based on what they find, your email goes to:

• The main Inbox
• The Spam or Promotions folder
• Or WORSE: gets blocked forever!

6. People React To Your Emails

How people interact is the most significant signal for ESPs. 

They observe,

• If they open, read, and reply – Congratulations!
• If they ignore or delete it. Not good. Try to find out the reasons for that. 
• If they raise a spam complaint (more than 0.1% of them) – Time to buy a new email and domain!

Your future email deliverability depends on this.

Why Do You Need a Strong Email Deliverability Infrastructure?

Before your email gets judged by inbox providers or spam filters, your email infrastructure gets judged first.

Here are the three main stages of email infrastructure setup:

1. Authentication Protocols (SPF, DKIM, DMARC)
2. Sending Domains
3. Mail Servers (IMAP/POP3, SMTP)

1. Authentication Protocols: Proving Your Emails Are Legit

These are like ID checks for your emails to pass ESP filters.  

Here’s how they work:

• SPF (Sender Policy Framework): Specifies which servers can send emails on your behalf.
• DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails, confirming they haven’t been altered.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Instructs email providers to handle emails that fail SPF or DKIM checks.

Too technical? Just know that this authentication communicates to ESP that, 

• “Yes, this email really came from your domain.”
• “No one is pretending to be someone else.”

If these authenticators aren’t set up, your emails will look unverified and suspicious and likely be rejected.

2. Sending Domains: Building and Protecting Your Reputation

Your domain name is a big trust signal.

Email service providers look at:

• How old is your domain?
• How often do you send emails?
• What do people do with those emails? (open, delete, reply)?

For example, a brand-new domain suddenly sending 500 emails looks like a spammer’s tactic. 

But a warmed-up domain with a solid track record is much more trusted — and more likely to land in the inbox.

3. Mail Servers: Powering Reliable Email Sending

Mail servers are like the post office for your email.

They manage how emails are sent and received.

• SMTP: Sends your emails out
• IMAP/POP3: Let you check replies or incoming messages

Don’t want to take the hassle of email infrastructure setup: Check this Top Email Infrastructure Providers in 2025

What Affects Your Email Deliverability

As you know by now, email deliverability is not one score from one source. It’s the result of many small signals that tell inboxes whether to trust you or not. 

In this section, I’ll share the factors most damaging to your email deliverability. 

1. Low Sender Reputation
2. Low IP Reputation
3. Irregular Sending Patterns
4. Missing Email Authentications
5. Spammy or Irrelevant Content
6. High Bounce Rate
7. High Spam Complaint Rate
8. Low Engagement Rates
9. Large Media Files
10. Getting Blacklisted

1. Low Sender Reputation

Sender reputation is also popularly known as Domain Reputation. 

It’s scored based on how trustworthy your behavior is with your prospects.

All in all, your sender reputation reflects, 

• Who (owner of the domain)
• What (content, intent, and relevancy of the emails)
• where (email lists)
• When (email volume and timings)

2. Low IP Reputation

The place you send emails from matters. And that is your IP address.  

ESPs track your IP address along with domain addresses.

If it has a bad history of spam reports or blacklists, your emails will likely be blocked or filtered into spam. 

3. Irregular Sending Patterns

ESPs expect gradual, consistent sending. (basically, how humans send!)

Random spikes or large jumps in volume and sending from domains that have been unused for years can trigger spam filters.

4. Missing Email Authentications

Without SPF, DKIM, or DMARC, emails can’t be sent. (Properly, at least!)

ESPs might think someone’s pretending to be you, and block your messages to stay safe.

5. Spammy or Irrelevant Content

Email content should have two things: Relevancy and Value!

So, if your message doesn’t match your audience’s wants, ESPs may lower your email deliverability due to poor engagement rates.

What kind of content hurts your deliverability?

• Sending emails that don’t match your audience’s interests
• Using spammy words like: “FREE!!!”, “Buy now”, “URGENT”, “Cash Prize”

Why? Because spammers use the same tricks.

Stick to clear, honest, human-sounding language. Add value in every email.

6. High Bounce Rates

If you’re sending emails to dead or fake addresses, that’s a big NO!

Inbox providers will see you as careless or worse, a spammer. 

Keep your bounce rate below 2%

More than that? Clean your list right away.

Always verify emails before hitting send. 

Tools like Saleshandy can help you with AI bounce detection and save your sender reputation. 

7. High Spam Complaint Rates

If even a single prospect raises a spam complaint against your email, ESPs take that very seriously!

An Ideal spam complaint rate is <0.1%. 

Yes, even a few complaints out of hundreds can damage your domain’s credibility.

8. Low Engagement Rates

No opens, no replies, no clicks = Poor Signals!

As this rate combines many rates, all the other inbox tracking rates should work together to produce a good engagement rate. 

Low engagement tells inboxes that your emails aren’t helpful, so they may stop delivering them to the primary inbox.

9. Large Media Files

Too many images, videos, or large files can raise suspicion as it looks like marketing gimmicks!

I recommend sending plain text cold emails with the highest email deliverability. 

But if you must add media, keep things in balance. 

Marketing emails maintain at least a 60:40 ratio for content and media. 

But cold emails should aim for an 100% ratio plain text!

10. Getting Blacklisted

If you’re on a blacklist, your email, domain, and future domains are also at risk!

What causes blacklisting?

• High spam complaints (The Main Reason!)
• Bad or fake email lists
• No email authentication
• Sudden spikes in volume

Once an email is blacklisted, fixing it is difficult, and emails won’t reach inboxes. So, try keeping it safe.

These were the main reasons, but for a complete list, see Email Deliverability Issues.

How To Improve Your Email Deliverability

In this section, I’ll share some of the best email deliverability practices to use in 2025. 

I have personally used them, and my clients do the same. 

1. Use Email Authentication to Build Trust
2. Warm Up Your Domain Before Sending at Scale
3. Set the Right Domain Classification for Better Reputation
4. Clean and Segment Your Email List Regularly
5. Avoid Spam Triggers in Email Content
6. Write Engaging Subject Lines and Personalized Content
7. Use a Real Reply Email and Easy Unsubscribe Link
8. Send Emails on a Consistent Schedule
9.  Follow Email Laws (Like GDPR & CAN-SPAM)

1. Use Email Authentication to Build Trust

Email providers trust authenticated senders more. (No points for guessing)

If you’re using SPF, DKIM, and DMARC (already set up), your emails will look safer and more legitimate. 

When these are set up properly, your domain tells inbox providers:

• “This email is real.”
• “This sender is verified.”
• “No spoofing going on here.”

That means fewer emails in spam, and more in the primary inbox.

2. Warm Up Your Domain Before Sending at Scale

New domains build reputations slowly. 

Start with low volume. Send to engaged contacts first. Gradually increase.

This prevents spam flags and builds sender credibility with inbox providers.

3. Set the Right Domain Classification for Better Reputation

Email service providers (like Gmail or Outlook) check how your domain is listed online.

If your domain isn’t classified under the correct industry or business type, it may confuse filters and hurt your reputation.

Setting the proper classification helps inbox providers trust your emails and deliver them to the inbox more often.

4. Clean and Segment Your Email List Regularly

Remove invalid, inactive, or bounced emails and group users by interests or actions.

A clean and segmented list lowers bounce rates, improves engagement, and shows that you’re sending relevant emails, one of the key signs ESP filters look for.

5. Avoid Spam Triggers in Email Content

Watch out for:

• Spammy words (e.g., “FREE!!!”, “100% guaranteed”)
• Large image-heavy emails
• Broken or shady-looking links
• Oversized attachments

Try a spam checker tool to analyze your emails before sending.

6. Write Engaging Subject Lines and Personalized Content

Generic = ignored.

Personalized = opened.

Use dynamic fields like first names, company names, or even recent activity. Match your subject line to something your recipient actually cares about.

Saleshandy personalization image here

Continue this in the body of the email as well. 

7. Use a Real Reply Email and Easy Unsubscribe Link

No-reply@yourcompany.com? Big mistake!

Let people reply – it improves deliverability.

Make your unsubscribe link clear and easy to find.

This reduces spam complaints and shows providers you respect recipients’ choices. 

8. Send Emails on a Consistent Schedule

Random email blasts hurt your reputation.

Send on fixed days and times. 

Consistency helps inbox providers trust your sending habits and improves delivery over time.

9. Follow Email Laws (Like GDPR & CAN-SPAM)

Always send emails with permission. 

Comply with:

• GDPR (Europe)
• CAN-SPAM (U.S.)
• Other local laws based on your audience’s region (more details Here)

Use clear opt-ins and honour unsubscribe requests fast.

Staying compliant protects you from legal issues and supports long-term deliverability.

Advanced Email Deliverability Techniques

If you’re sending cold email campaigns in 2025, Tools Matter!

Modern email tools come with smart features designed to protect your sender reputation and maximize your inbox placement.

1. AI Bounce Detection
2. AI Content Spam Checker
3. Email Account Health Check
4. Sender Rotation

1. AI Bounce Detection: Catch Problems Before They Happen

Not all bounces are the same, and AI helps you treat them differently.

It automatically distinguishes:

• Hard bounces (permanent issues like invalid emails)
• Soft bounces (temporary issues like full inboxes)

Pro Tip:

Saleshandy’s AI monitors bounce patterns. If it detects five consecutive bounces, it automatically pauses your campaign to protect your deliverability.

No manual checks. No damage to your sender reputation. 

2. AI Content Spam Checker

Before sending out emails, the AI Spam Checker evaluates the content and subject lines of your emails to predict the likelihood of them being marked as spam. 

By identifying potential issues beforehand, you can make necessary adjustments to ensure your emails land in the inbox.

3. Email Account Health

This feature lets you identify, track, and take action on email deliverability-related issues quickly. 

From one dashboard, you can track authentication stats, blacklists, sending volumes, engagement metrics and much more.

3. Sender Rotation

Sending all your cold emails from one account? Bad idea.

With Sender Rotation, your campaigns are split across multiple email accounts. This:

• Mimics natural sending behavior
• Prevents overload on one account
• Reduces spam flags and blacklisting risk
• Keeps your deliverability stable

Key Metrics For Email Deliverability

If you want better deliverability, you need to track these metrics.

These are the exact metrics experts check daily to avoid spam and achieve 95%+ email deliverability every time!

For Example: “A manufacturer registered as a supplier, and a wrong message was sent!”

P.S. Advanced outreach tool dashboards usually have most of them in one place. (like Saleshandy).

1. Bounce Rate
2. Inbox Placement Rate
3. Click-Through Rate
4. Spam Complaint Rate
5. Authentication Success

1. Bounce Rate

Keep It Under 2%

• Danger Zone: Over 5%
• Good Zone: Under <2%

2. Inbox Placement Rate

Aim for 95%+ inbox delivery

• Above 95% = Great
• Below 85% = You’re likely hitting spam

3. Click-Through Rate (CTR)

A healthy range is 2% to 5%

It varies from industry to industry. 

4. Spam Complaint Rate

Keep it below 0.1%

Spam complaints will crush your domain. So keep extra attention on this metric. 

If this goes up, pause the campaign immediately.

5. Authentication Success

The goal here is 100% only.

SPF, DKIM, and DMARC need to pass for every email.

If even one fails, your chances of inbox placements drop fast.

What are Some Email Deliverability Test Tools?

Testing email deliverability helps you catch issues before your emails land in spam. 

Here are a few essential tools (grouped by category) that experts use to monitor, test, and fix deliverability.

1. Seed Testing Tool
2. Content Analysis Tool
3. Inbox Placement Tools
4. Blacklist Detection Tool

1. Seed Testing Tool

This tool tests deliverability using real inboxes across multiple email providers.

Tool Suggestion: Validity

Place “seed” emails in actual inboxes to track exactly where your email lands and why.

2. Content Analysis Tool

This table checks if your email content is triggering spam filters.

Tool Suggestion: GlockApps

Gives you a spam score and points out what to fix in your subject line, email body, or headers.

3. Inbox Placement Tools

An inbox placement tool helps test whether your emails will land in the primary inbox, spam, or other folders.

Tool Suggestion: Saleshandy’s Inbox Radar

It helps you automate inbox placement tests, provides actionable deliverability insights, offers real-time reputation monitoring, alerts you to spam trigger content, and performs technical authentication checkups.

4. Blacklist Detection Tool

These tools help find out if your domain or IP is blacklisted.

Tool Suggestion: Talos Intelligence (Cisco) 

Scans global blocklists to see if your emails are being blocked due to a poor IP reputation.

Want to see more email deliverability tools? I have got it!

Laws and Policies: What You Must Follow to Stay Compliant

Every country has its own set of laws to protect people’s privacy and stop spam. 

If you send marketing or outreach emails, these rules apply whether you send them locally or internationally.

Here’s a quick guide to the major laws and platform-level policies that matter in 2025

• Email Laws by Country
• Platform Policies to Watch in 2025

Email Laws by Country

1. USA
2. EU
3. Canada
4. UK
5. Australia
6. New Zeland
7. India

1. CAN-SPAM Act (USA)

Requires clear opt-outs, accurate sender info, and honest subject lines.

2. General Data Protection Regulation – GDPR (EU)

You must have consent to email people. Also includes strict data privacy rules.

3. CASL – Canada’s Anti-Spam Law (Canada)

Consent is a must. Emails need full sender details and unsubscribe options.

4. PECR – Privacy and Electronic Communications Regulations (UK)

Similar to GDPR but with added rules around tracking, cookies, and email marketing.

5. Australian Spam Act

Emails must be sent with permission, including the sender ID, and users must be given a way to opt out.

6. New Zealand’s Unsolicited Electronic Messages Act

Focuses on consent, accurate info, and clear opt-out links.

7. India – IT Act 2000 & IT (Amendment) Act 2008

Regulates electronic communication and privacy, including email usage for commercial purposes.

Platform Policies to Watch in 2025

Here are 3 platform-level policies you must follow:

1. Google Sender Guidelines
2. Microsoft Outlook Rules
3. Yahoo Sender Rules

Google Sender Guidelines

• Authenticate with SPF, DKIM, and DMARC
• Include unsubscribe links
• Maintain low spam complaints and bounce rates

🔗 Google Email Sender Guidelines

Microsoft Outlook (Microsoft 365)

• Avoid bulk sends without engagement history
• Don’t send from new/unwarmed domains
• Stay off Microsoft’s internal blocklists

🔗 Microsoft Bulk Sender Rules

Yahoo Sender Rules

• Use proper authentication
• Avoid spammy subject lines
• Keep engagement rates high

🔗 Yahoo Mail Best Practices

Email Deliverability Key Takeaways: Dos and Don’ts

To sum up, I have created this Dos and Don’ts table. Read and quickly revise what you just learned.

Email Deliverability: FAQs

1. What is meant by email deliverability?

Your email’s ability to be delivered to an inbox is known as its deliverability.

2. How do you ensure email deliverability?

There are many things you can do to ensure email deliverability.

Starting from authenticating your domains, having trustworthy email service providers, writing amazing email subject lines, keeping the content spam free, sending to the right set of people, and many more

3. What is a good email deliverability rate for email?

Everyone has the question about what a good email deliverability rate is in cold emailing.

A good email deliverability rate is somewhere between 95% to 99%. This means that for every 100 cold emails you send, at least 95 of them should reach the recipient’s inbox. 

4. What hurts email deliverability?

Many factors can affect your email deliverability, such as a poor sender’s reputation, spam complaints, high bounce rates, and irregular sending patterns. 

5. What are the best email deliverability practices?

While there are many best practices for email deliverability, I will help you with the most important ones here. 

• Have a proper Technical Setup. – Secure your emails using DKIM, DMARC, SPF, and ARC. Make sure you pass the authentication.
• Use a trustworthy and dedicated IP address.
• Maintain a clean and well-segmented email list.
• Create well-written, valuable, engaging, and relevant content.
• Optimize your subject line using personalization.
• Balance the image and text ratio.
• Warm up your IP address before bulk sending.
• Use feedback loops.
• Ensure GDPR compliance.