Aastha Shaw / Updated: March 14, 2025

Email Bounce Rate - Causes & Proven Ways To Reduce It

Bounce rate is one of the key email metrics you can’t afford to overlook.

No matter how compelling your content or well-crafted your campaign is, if your emails aren't reaching recipients' inboxes, all your efforts will be in vain.

But what happens when your emails "Bounce"? How do you measure it?

More importantly, how can you improve your bounce rates and boost email deliverability?

This guide breaks down everything you need to know about email bounce rates—from what they are to actionable strategies for reducing them.

● What is Email Bounce Rate?
● Hard Bounces vs. Soft Bounces: What’s the Difference?
● How to Measure Bounce Rate?
● What is The Standard Bounce Rate?
● Should You Delete Contacts with a Bounce Rate?
● Reasons For a High Bounce Rate
● How to Reduce Email Bounce Rates - 9 Proven Ways!
● How Clearout Will Help You Bounce Back Stronger!

What is Email Bounce Rate?

Email Bounce Rate is defined as the percentage of emails that can’t be delivered to a recipient’s inbox. Bounces happen for a variety of reasons, from incorrect email addresses to inboxes that are too full to receive new messages.

While a low bounce rate is a sign of a healthy email list, a high bounce rate could spell trouble for your campaign's performance—and even your sender reputation.

Hard Bounces vs. Soft Bounces: What’s the Difference?

Understanding the types of bounces is crucial when facing deliverability issues. There are two major types: hard bounces and soft bounces.

1. Hard Bounces

A hard bounce is a permanent failure. This happens when an email cannot be delivered due to a persistent problem, like an invalid or nonexistent email address. Common causes include:

Nonexistent email addresses: The address is misspelled, or the domain no longer exists.
Invalid email formatting: The email address is improperly formatted (e.g., "john.doe@com" instead of "[email protected]").

Why should you care?

A high rate of hard bounces can severely damage your sender reputation, leading to future emails being flagged as spam or rejected altogether by Internet Service Providers (ISPs).

2. Soft Bounces

A soft bounce is a temporary delivery failure, usually caused by short-term issues on the recipient's side. Common reasons for soft bounces include:

Full inboxes: The recipient's inbox is at capacity and cannot accept any more messages.
Temporary server issues: The recipient’s mail server is temporarily unavailable or overloaded.
Large attachments: The email exceeds the recipient's maximum file size limit.

Soft bounces can often be resolved over time, so they don't carry the same long-term risks as hard bounces.

How to Measure Bounce Rate?

This is how you can calculate Bounce Rate:

For instance, if you send out 1,000 emails and 80 bounce back, your bounce rate would be 8%.

What is The Standard Bounce Rate?

While the bounce rate can differ from industry to industry, here is an overview of what is considered good or bad:

Excellent: Below 2%
Acceptable: 2%–5%
Problematic: Above 5%

According to industry benchmarks:

Retail often sees bounce rates as low as 0.24%.
Education and Non-Profits may experience a slightly higher rate, around 0.46%.

Should You Delete Contacts with a Bounce Rate?

The answer is ‘YES’—especially for Hard Bounces.

Contacts that consistently result in bounces should be removed from your email list to maintain your sender reputation and ensure you're only engaging with real subscribers.

For soft bounces, consider removing contacts that have repeatedly bounced over a period of time. This might indicate that their email address is no longer valid or that they’re not engaged with your content.

Reasons For a High Bounce Rate

Spam Traps
Spam traps are fake email addresses used by ISPs to catch spammers, mostly added to your list by third-party services or malicious actors. Sending to one can damage your sender reputation.
Invalid Email Addresses
Invalid email addresses often result from typos during sign-up, deactivated accounts, or users failing to update their contact details. This results in hard bounces, which can negatively impact deliverability.
Full Inboxes
If a recipient’s inbox is full, the email will bounce back and will be marked as undelivered. While this is a soft bounce, it’s still something to monitor as it harms email deliverability.
Blocked by ISPs
ISPs can block your emails if your domain or IP address is flagged for spam or suspicious activity, often due to excessive or rapid email sending or being listed on a blacklist.
Large Attachments
Emails with large attachments can trigger bounces even if the email address is invalid as they exceed the file size limits set by some email servers.

📌 Struggling with spam traps? Try Clearout to identify and remove them from your list

How to Reduce Email Bounce Rates - 9 Proven Ways!

1. Keep a Pristine Email List: Quality over Quantity

Buying email lists may seem like a quick way to expand your reach, but it’s a risky move that can hurt your email campaign's performance and often harm your sender score. Purchased lists contain outdated, fake, or inactive email addresses, leading to high bounce rates and damaging your sender reputation.

You significantly increase the risk of hard bounces, which can make it much harder for your future emails to reach inboxes instead of ending up in spam folders.

Your Next Move?

Focus on building an organic list through opt-in forms and engagement.
Re-engage inactive subscribers with win-back campaigns to lower bounce rates.
Remove inactive subscribers periodically, particularly those who haven’t engaged in 6–12 months.

Why: Studies show that regular list cleaning can significantly reduce bounce rates and increase open rates up to 50%.

👉 Must Read: 6 Better Alternatives To Buying Lists!

2. Go Double Opt-In

Double opt-in requires users to confirm their subscription via a secondary email, ensuring only genuinely interested subscribers are in your email lists, reducing the chances of sending messages to invalid or fake addresses.

Your Next Move?

Send a confirmation email immediately after signup.
Automate the process to filter out fake addresses before they reach your list.

Why: This reduces spam trap risks and minimizes typos, resulting in higher engagement and lower bounce rates.

3. Verify and Validate Before You Send

Using email validation tools helps you clean your list before each campaign, reducing the risk of sending emails to invalid or expired addresses that cause hard bounces.

Your Next Move?

Use tools like Clearout for bulk email verification to clean your list in one go.
Look for services that offer real-time validation during the sign-up process to prevent invalid entries.

Why: Validation tools can significantly decrease your bounce rate. Clearout helps you minimize your bounce rate to 0-2%.

4. Authenticate Your Emails

Email authentication protocols establish your credibility as a sender and improve deliverability by ensuring ISPs recognize your messages as legitimate. This prevents the emails from being marked as spam or rejected by the recipient’s mail servers

Your Next Move?

Configure SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) for your email domain.
Regularly monitor your domain reputation using tools like Google Postmaster.

Why: Authentication can improve inbox placement rates while protecting your domain from spoofing attacks.

5. Target Smarter, Not Harder (list segmentation)

Segmenting your email list ensures you send relevant content to the right people. This boosts engagement and reduces the risk of recipients marking emails as spam or ignoring them.

One effective approach is segmenting your email list based on- Subscriber Engagement.

Identify your most active subscribers—those who consistently open and interact with your emails—and communicate with them more frequently with offers and discounts to make the most out of this campaign and improve ROI.

Your Next Move?

Take time to analyze your list and learn more about the subscribers.
Then select the right email segmentation strategies like grouping subscribers by demographics, preferences, and engagement levels.
Customize email campaigns for each segment, offering personalized content that aligns with their needs.
Consider reducing the frequency of emails to users with full inboxes. Also, segment your audience to avoid overloading those who may not be as engaged.

Why: Segmented email campaigns have a 14.3% higher open rate and significantly lower bounce rate compared to non-segmented campaigns.

6. Keep it Simple: Limit the attachments

Large attachments can cause soft bounces by exceeding size limits or triggering spam filters. Some servers also block them to prevent spam or malware, so it’s best to limit their size or use cloud storage links.

Your Next Move?

Compress files and use cloud storage solutions (like Google Drive or Dropbox) to share large files instead of attaching them directly to your emails.
If attachments are necessary, ensure they are small, relevant, and virus-free or you could also try sending them in separate emails to avoid triggering file size limits.

Why: Emails without attachments are 2.5 times more likely to reach inboxes successfully.

7. Monitor Sender's reputation

Your Sender Reputation directly affects whether your emails are delivered or blocked. High bounce rates signal poor sender behavior, leading to penalties from ISPs. Therefore, it is extremely important to check and improve your sender reputation regularly.

Your Next Move?

Use platforms like Sender Score or Postmark to track your Sender Reputation.
Avoid sending too many emails at once to prevent being flagged by ISPs.
Avoid sending emails to purchased or outdated lists.

Why: A sender score above 90 ensures reliable inbox placement for your campaigns.

8. Use a Reputable ESP and Corporate Sender Domain

A reliable ESP(Email Service Provider) offers powerful deliverability features and good sender practices, helping to manage bounce rates and ensure your emails reach inboxes.

Additionally, free sender domains, such as Gmail, are more prone to being flagged by spam filters since scammers frequently use them for malicious activities.
Recipients are less likely to trust emails sent from a generic domain, and they may even block your email address.

Your Next Move?

Choose an ESP that prioritizes compliance and offers advanced tools like list cleaning, engagement tracking, and reputation monitoring.
Opt for an ESP with a proven track record of high deliverability rates.
Use a custom, branded domain for sending emails instead of free sender domains.

Why: Average deliverability rate of all ESPs is between 83 and 89%. But some good ESPs like ActiveCampaign and Mailchimp offer a 92%+ deliverability rate on average.

9. Play By the Rules: Stay Compliant, Stay Trusted

Following industry standards and regulations like CAN-SPAM, GDPR, and CASL not only ensures legal compliance but also helps maintain a good sender reputation.

Your Next Move?

Include an easy way to opt-out or Unsubscribe button for recipients.
Be transparent about how you handle email addresses and personal information.
Regularly review practices to meet updated legal requirements.

Why: Staying compliant reduces spam complaints, builds ISP trust, and enhances inbox placement, ensuring your campaigns are effective and lawful.

What It Means for Your Email Deliverability?

A low bounce rate signals to ISPs that you’re a reliable sender, increasing the chances of your emails reaching the inbox instead of spam.

While a 2-3% bounce rate is acceptable, anything over 5% raises red flags and can damage your sender reputation.

High bounce rates suggest poor email practices and list quality, prompting email service providers to flag your messages, even for engaged recipients. This impacts engagement, click-through rates, and ultimately, sales.

Every bounced email harms your digital reputation, making it vital to keep your lists clean, verify addresses, and reduce bounces to protect your deliverability and marketing success.

How Clearout Will Help You Bounce Back Stronger!

Now that you're equipped with the knowledge to tackle email bounce challenges, Clearout provides the perfect solution.

Clearout is among the leading AI-based Email Verification Tool. It validates your email list with 99% accuracy and identifies invalids, typos, spam traps, disposables, bounces, catch-alls, and more.

It offers insights and features that can bring down email bounces, and ensures your emails always land in the right inbox.

How?

Real-Time Email Validation - Ensures only valid contacts enter your database
Bulk List Cleaning - Regularly removes outdated, invalid, and risky email addresses that can result in bounces
Guaranteed Deliverables - Minimizes your bounce rate down to 0-3%
AI Verdict - Offers insights to plan your campaigns better & get less bounces
Allowlist/Blacklist Settings - Decide which emails and domains can enter your database and which should be blocked
Advanced Analytics & Reports - To keep a close check on your list quality and validations
Integrations - Clearout seamlessly connects with most CRMs, ESPs, Forms, and Sales tools to allow easy data cleaning and management.

Create a Healthy Email List & Boost Deliverability

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Email Bounce Rate - Causes & Proven Ways To Reduce It

Table of contents:

What is Email Bounce Rate?

Hard Bounces vs. Soft Bounces: What’s the Difference?

1. Hard Bounces

2. Soft Bounces

How to Measure Bounce Rate?

What is The Standard Bounce Rate?

Should You Delete Contacts with a Bounce Rate?

Reasons For a High Bounce Rate

How to Reduce Email Bounce Rates - 9 Proven Ways!

1. Keep a Pristine Email List: Quality over Quantity

2. Go Double Opt-In

3. Verify and Validate Before You Send

4. Authenticate Your Emails

5. Target Smarter, Not Harder (list segmentation)

6. Keep it Simple: Limit the attachments

7. Monitor Sender's reputation

8. Use a Reputable ESP and Corporate Sender Domain

9. Play By the Rules: Stay Compliant, Stay Trusted

What It Means for Your Email Deliverability?

How Clearout Will Help You Bounce Back Stronger!

Create a Healthy Email List & Boost Deliverability

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