Email Bounce Back: Meaning and Solutions

Created On:
July 16, 2022
Updated On:
February 20, 2024
Email Bounce Back

The bounce-back message is a common issue that can occur for several reasons. Whether we're sending a large mailing list or the mail copy is simply not reaching our recipients, understanding email bounced back meaning and how to fix it is crucial for successful email marketing.  

In this post, we'll discuss bounce back and how to troubleshoot it, so our outreach messages get through to the subscribers. Let's get started!

Email Bounce Back Meaning

It is a common issue that many marketers face today. A bounce back occurs when a cold message is undeliverable. Often resulting in a hard bounce, an email deliverability issue, or a spam report. It can indicate a problem related to the domain specified in the email addresses or matters associated with the sender's mail server being blocklist. 

Whether caused by flaws on the part of the sender or receiver, it can be frustrating when we send out a mass outreach campaign and get the most undeliverable mail count with a high bounce rate. 

And generally, two types of email bounces occur when we set up a cold campaign. Let us see the types of bounces in detail.

Soft Bounce

It is like a temporary issue or delay in sending the message. When we get a "soft bounce back email message" notice from the email provider, there's not necessarily anything wrong with the email sender or the recipient. Soft bounces can happen for many reasons, including full mailboxes, large file size, server issues, out-of-office status messages, etc. It is sorted in minimal time without spending any money. 

Hard Bounce

A hard bounce back email is more serious than a soft return and requires direct attention. Hard bounces happen when a mail server can't find any route to deliver the message. It includes typo errors, invalid addresses, blocked mails, or non-existent spam mails. No one wants to receive a hard bounce-back, but this could mean that our mail copy gets caught in spam filters, and we lose our chance to communicate with the prospects.

What Causes the Bounced Mails?

The most common reasons behind bounces are permanent or temporary issues with the email account, the sending to receiving mails, or the receiving server blocking our content. In some situations, we have to wait for some time after an error message until it's resolved by the user who blocked us, and also, there might be a permanent block.

Here are some reasons for bounce back:

  • Invalid address: A missed typed email id by human error or a non-existent email address can cause a bounce back.
  • Spam filters blacklisting: Once our domain is added to the blocklist database, the sending process on that server status becomes permanently disabled. It becomes difficult to avoid these blocklists since they are frequently updated automatically by local ISPs and Search engines' databases. It destroys the sender's reputation.
  • Relevant content: Creating relevant messages is highly important. Otherwise, the mass mailing with repetitive and irrelevant content in bulk lands our messages in spam folders.
  • DNS Failure: It happens when the server-side issue has been raised. When we send a message, the domain is responsible for email deliveries. If the mailing domain and all the records are perfect, it will not cause any problem. Otherwise, it will result in bounced back email.
  • Undeliverable emails: It may happen when the recipient-side email service provider has a server issue, maintenance issue, or is temporarily unavailable. But if it is frequent, the domain is permanently crashed or removed.
  • Large attachments: it will happen when the attachment size exceeds the email server limits. The recipient server blocks the sender domain.

Why Do the Bounce Back Need to be Resolved?

The bounce rate is why we should correct our mailing issues as soon as possible. An email bounce rate is an amount of outreach copies queued that do not reach their destination. It indicates how successfully our cold outreach campaigns are being sent out and if they need to change anything to keep up with demand.

And it plays a major role in campaign success and conversion rate. Also, the sooner a bounce back can be resolved, the less likely it will affect our campaigns. The bounce-back message is usually scary, but avoiding it helps improve the bounce rate and campaign success.

It is time to share how we can overcome the Bounced backs issue and achieve maximum conversion from campaigns.

How to Fix Email Bounce Backs?

It sounds like you're experiencing some problems with your bounced back email, so we'll want to look at what might be going wrong and how best to approach this issue. First, let us explain two situations when sending out cold messages. One is before someone enters their information into our website, and the other is where they have already submitted but no active payment. So we need to ensure that our mail doesn't bounce back. Here are some effective ways to overcome email bounce back message:

Verify the Email List Details

Maintain the email list hygiene. If the client's contact address is invalid, stop the campaign immediately. Check the availability of the contact IDs first to avoid delivery failure. If available, try to resend the messages with a different mail address and improve the email bounce rate. And verifying the large customer base is quite easy nowadays with AI marketing automation tools. It allows us to verify the lead list in bulk and helps us to reduce the bounce rate. And the cold outreach messages to the potential list help us get more sales opportunities. 

Email List verification with Smartwriter

Try Double Opt-in

We recommend a double opt-in process to avoid bounces. It is done by asking users to confirm their contact IDs twice. Once on the signup page and again after clicking the submit button. It ensures that the user is fully aware of the subscription process and that the mail address is genuine.

Use Double Opt-out

It is one of the common reasons behind email bounce. We recommend using the double opt-out method to avoid bounces. In this case, the user needs to click on the unsubscribe link to stop receiving any further communication.

Optimize Content

Include relevant links in the email body. Make sure that the subject line is short, clear, and informative. Include images or videos in the content copy so recipients can see them easily.

Send to the Right Recipient

If the bounce back occurs, we have to check whether the message is sent to the right person or not. If it happens because of an incorrect recipient name, send the same message again with the corrected recipient details.

Send the Cold Messages at the Right Time

Don't send the messages too early or late. Send the email at the right time. According to statistics, marketers prefer to set up campaigns in the first three days of the week, which results in high conversions. So the earlier we send the messages, the better our chances of getting a response. But if you send it too early, it may result in the loss of the opportunity.

Check the Delivery Status

Checking the delivery status of the campaign is very important. It would be best if we always verify the delivery status of the emails. If it did not reach the inbox, try to resend it again. As a sales professional, maintaining reputation is important. It helps in getting high opens and deliverability. The email automation tools allow us to track the campaign delivery status.

Email delivery status check

Domain Authentication

Authenticating the email domain will improve trustworthiness among the service provider, which will help us increase the deliverability rate and mainly reduce the email bounce rate. It's a simple way to improve how people receive mail from their customers and boost the sender's reputation.

Use Spintax

To land in an email client's mailbox, the structure of our message copy matters the most. The spintax check helps us send our message directly into customers' inboxes, avoid spam emails and achieve a maximum reply rate. 
In fact, as per our research campaigns with spintax achieve a higher reply rate, with an increase ranging from 17% to 28%.

Campaign Performance Track with SmartLead

Set Email Marketing Campaign with Dynamic IP Address

When we send bulk emails many times from the same IP address, the chances of our domain getting a blocklist are high. Because some servers may consider our messages as unsolicited emails, to help us with this, the AI cold outreach software comes to the rescue. Its extraordinary features allow us to set different Ip addresses for each and help us land in prospects' inboxes.

Plan According to the Types of Email Bounce Messages

The soft bounces like a full mailbox and temporary server downs are sorted immediately by suggesting old blog removal or waiting helps to overcome the situation. If it is a hard bounce message, then something might be wrong with our copy, so it's important to optimize and follow standards like no typo errors, avoid using special characters, and using recommended-sized files. It will help save bandwidth.

How does Smartlead handle the bounces?

Smartlead is the Best AI marketing tool to automate your campaign. The exciting feature of the tools helps us reduce the bounce rate and improves campaign performance. Here are a few ways Smartlead can handle email bounces.

  • It allows us to send unlimited emails with auto-rotating mail IDs as options to enhance sender reputation.
  • To directly land in clients' inboxes, it helps with its dynamic IP address per campaign and boosts our ROI.
  • It provides spintax checks and helps to avoid spam folders. It also improves the reply rates.
  • It helps to achieve 97% of deliverability with email warm-up options and scale up our reputation. 
  • Providing the spam trigger check feature avoids the spam blocker and massively improves the deliverability and far more.
SmartLead to avoid Email Bounce Backs


Bounce back is a common issue caused by many things such as an invalid email address, a full mailbox, or server problems. Now that you the email bounce back meaning, you don't need to panic when you get a non-delivery report as a response. Because there are ways to fix bounce backs and ensure your outreach copies are delivered to your subscribers' inboxes. To avoid bounces and keep your customer base healthy, ensure accurate subscriber data, use confirmed opt-in, test your content before sending it out, and monitor the deliverability. Have you ever experienced bounced emails? What solutions did you try? Let us know!


1. Why are my emails bouncing back?

There are many reasons why your emails might bounce back. The possible reasons are: the recipient's inbox is full, 'spam' flagged content in the email body, the recipient's email address does not exist, poor sender reputation, or a restrictive DMARC record for your domain.

2. How to do email bounce back check?

There are many tools such as MXToolbox, where you can simply enter the email bounce error code (SMTP Error Code) and check the issue.

3. Why did my email bounce back when the email address is correct?

There are several reasons why an email might bounce back even if the email address is correct. Some common causes include the recipient's inbox being full, a temporary issue with the recipient's email server, or the recipient's email address being misspelled in your contact list. Additionally, your email server may have been flagged as spam by the recipient's email provider.

4. How can I differentiate between a hard bounce and a soft bounce?

A hard bounce occurs when an email is permanently rejected due to reasons like an invalid or non-existent email address. On the other hand, a soft bounce is a temporary issue, like the recipient's inbox being full or a server problem. Soft bounces may be retried for a certain period before they become a hard bounce.

5. What are the common reasons for emails bouncing back?

Common reasons for emails bouncing back include:

  • Invalid or non-existent email addresses.
  • Recipient's inbox being full.
  • Temporary server issues on the recipient's side.
  • Your email server being flagged as spam.
  • Content triggering spam filters.
  • Sender reputation issues.

6. How can I reduce my email bounce back rate?

To reduce your email bounce back rate, consider the following steps:

  • Ensure your email list is up-to-date and regularly clean out invalid or inactive addresses.
  • Use double opt-in to verify subscribers' email addresses.
  • Monitor your sender reputation and take action to improve it if needed.
  • Avoid using spammy language or content in your emails.
  • Use a reputable email service provider with good deliverability rates.
  • Implement proper SPF, DKIM, and DMARC authentication to verify your domain.

7. Is there a way to get feedback on why an email bounced back?

Yes, some email service providers and software platforms offer bounce-back reports that provide detailed information on why an email bounced. These reports may include specific error codes, which can help you pinpoint the exact issue. Additionally, you can set up a dedicated email address to receive bounce notifications, allowing you to track and address bounce-backs more effectively.

What’s a Rich Text element?

The rich text element allows you to create and format headings, paragraphs, blockquotes, images, and video all in one place instead of having to add and format them individually. Just double-click and easily create content.

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Static and dynamic content editing

A rich text element can be used with static or dynamic content. For static content, just drop it into any page and begin editing. For dynamic content, add a rich text field to any collection and then connect a rich text element to that field in the settings panel. Voila!

How to customize formatting for each rich text

Headings, paragraphs, blockquotes, figures, images, and figure captions can all be styled after a class is added to the rich text element using the "When inside of" nested selector system.

Author’s Details

Nandhini C

Nandhini is a Senior SEO Analyst at the Smartwriter. She's always on top of new trends and technologies to stay ahead in this ever-changing industry. Her strengths are SEO, Lead generation, email campaigns, website optimization for search engines, link building, and making search better.


Edited by:

Charu Mitra Dubey


Frequently asked questions

General Questions

What is Smartlead's cold email outreach software?

Email automation FAQs- Smartlead

Smartlead's cold email outreach tool helps businesses scale their outreach efforts seamlessly. With unlimited mailboxes, fully automated email warmup functionality, a multi-channel infrastructure, and a user-friendly unibox, it empowers users to manage their entire revenue cycle in one place. Whether you're looking to streamline cold email campaigns with automated email warmups, personalization fields, automated mailbox rotation, easy integrations, and spintax, improve productivity, or enhance scalability with subsequences based on lead’s intentions, automated replies, and full white-label experience, our cold email tool implifies it in a single solution.

How does the "unlimited mailboxes" feature benefit me?

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Our "unlimited mailboxes" feature allows you to expand your email communications without restrictions imposed by a mailbox limit. This means you won't be constrained by artificial caps on the number of mailboxes you can connect and use. This feature makes Smartlead the best cold email software and empowers you to reach a wider audience, engage with more potential customers, and manage diverse email campaigns effectively.

What do you mean by "unibox to handle your entire revenue cycle"?

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The "unibox" is one of the unique features of Smartlead cold email outreach tool, and it's a game-changer when it comes to managing your revenue cycle. The master inbox or the unibox consolidates all your outreach channels, responses, sales follow-ups, and conversions into one centralized, user-friendly mailbox.

With the "unibox," you gain the ability to:
1. Focus on closing deals: You can now say goodbye to the hassle of logging into multiple mailboxes to search for replies. The "unibox" streamlines your sales communication, allowing you to focus on what matters most—closing deals.

2. Centralized lead management: All your leads are managed from one central location, simplifying lead tracking and response management. This ensures you take advantage of every opportunity and efficiently engage with your prospects.

3. Maintain context: The "unibox" provides a 360-degree view of all your customer messages, allowing you to maintain context and deliver more personalized and effective responses.

How does Smartlead ensure my emails don't land in the spam folder?

Email automation FAQs- Smartlead

Smartlead, the best cold email marketing tool, ensures your emails reach the intended recipients' primary inbox rather than the spam folder. 

Here's how it works:
1. Our "unlimited warmups" feature is designed to build and maintain a healthy sending reputation for your cold email outreach. Instead of sending a large volume of emails all at once, which can trigger spam filters, we gradually ramp up your sending volume. This gradual approach, combined with positive email interactions, helps boost your email deliverability rates.

2. We deploy high-deliverability IP servers specific to each campaign. 

3. The ‘Warmup’ feature replicates humanized email sending patterns, spintax, and smart replies.
4. By establishing a positive sender reputation and gradually increasing the number of sent emails, Smartlead minimizes the risk of your emails being flagged as spam. This way, you can be confident that your messages will consistently land in the primary inbox, increasing the likelihood of engagement and successful communication with your recipients.

Can I integrate Smartlead with other tools I'm using?

Email automation FAQs- Smartlead

Certainly, Smartlead is designed for seamless integration with a wide range of tools and platforms. Smartlead offers integration with HubSpot, Salesforce, Pipedrive, Clay, Listkit, and more. You can leverage webhooks and APIs to integrate the tools you use. Try Now!

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What type of businesses sees the most success with Smartlead?

No, there are no limitations on the number of channels you can utilize with Smartlead. Our multi-channel infrastructure is designed to be limitless, allowing you to reach potential customers through multiple avenues without constraints.

This flexibility empowers you to diversify your cold email outreach efforts, connect with your audience through various communication channels, and increase your chances of conversion. Whether email, social media, SMS, or other communication methods, Smartlead's multi-channel capabilities ensure you can choose the channels that best align with your outreach strategy and business goals. This way, you can engage with your prospects effectively and maximize the impact of your email outreach.

Email automation FAQs- Smartlead

Do you provide me with lead sources?

Smartlead distinguishes itself from other cold email outreach software by focusing on limitless scalability and seamless integration. While many similar tools restrict your outreach capabilities, Smartlead offers a different approach.

Here's what makes us uniquely the best cold email software:

1. Unlimited Mailboxes: In contrast to platforms that limit mailbox usage, Smartlead provides unlimited mailboxes. This means you can expand your outreach without any arbitrary constraints.

2. Unique IP Servers: Smartlead offers unique IP servers for every campaign it sends out. 

3. Sender Reputation Protection: Smartlead protects your sender reputation by auto-moving emails from spam folders to the primary inbox. This tool uses unique identifiers to cloak all warmup emails from being recognized by automation parsers. 

4. Automated Warmup: Smartlead’s warmup functionality enhances your sender reputation and improves email deliverability by maintaining humanized email sending patterns and ramping up the sending volume. 

5. Multi-Channel Emphasis: Smartlead places a strong emphasis on multi-channel outreach. You can reach your prospects where they are with the LinkedIn outreach feature.   With Smartlead’s cold email automation software, you're always one step ahead in your outreach efforts, enjoying the freedom to scale your initiatives and seamlessly integrate with other tools—all while maintaining a focus on maximizing the impact of your outreach.

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How secure is my data with Smartlead?

Ensuring the security of your data is Smartlead's utmost priority. We implement robust encryption methods and stringent security measures to guarantee the continuous protection of your information. Your data's safety is paramount to us, and we are always dedicated to upholding the highest standards of security.

How can I get started with Smartlead?

Email automation FAQs- Smartlead

Getting started with Smartlead is straightforward! Just head over to our sign-up page and follow our easy step-by-step guide. If you ever have any questions or need assistance, our round-the-clock support team is ready to help, standing by to provide you with any assistance you may require. Sign Up Now!

How can I reach the Smartlead team?

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We're here to assist you! You can easily get in touch with our dedicated support team on chat. We strive to provide a response within 24 hours to address any inquiries or concerns you may have.

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