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How to Fix Bounced Emails: 10 Effective Solutions for Your Campaigns

Struggling with bounced emails? Discover 10 effective solutions to fix and prevent them. Improve your email campaigns with practical tips and strategies.
Written by
Harsh P
Published on
June 20, 2024

Introduction to Email Bounce

Introduction to Email Bounce

An email bounce occurs when your email fails to reach the recipient's mailbox due to certain issues. Your email service provider sends you a bounce-back message called a Non-Delivery Report (NDR), detailing the failure and technical reasons.

Bounced emails can harm your email account by making it more susceptible to spam filters, reducing your sender score and deliverability rate. It's crucial for email marketers to understand different types of email bounces and how to prevent them.

Any marketer, salesperson, or professional involved in outreach would want to avoid email bounces. 

Why Do Email Bounce Back

Emails can bounce back for several reasons, each impacting your email deliverability and sender reputation. Here are some common causes:

  1. Invalid Email Addresses: Sending emails to addresses that don't exist or contain typos will result in bounces.
  2. Full Mailboxes: If the recipient's mailbox is full, your email cannot be delivered and will bounce back.
  3. Server Issues: Problems with the recipient's email server, such as being down or misconfigured, can cause bounces.
  4. Spam Filters: If your email content is flagged as spam, it may be rejected by the recipient's email server.
  5. Blocked Email Address: The recipient's email server may block your address due to previous issues or low sender reputation.
  6. Large Attachments: Emails with large attachments can bounce if they exceed the recipient's server size limits.
  7. Blacklisted IP Address: If your sending IP address is blacklisted, your emails will likely be blocked and bounce back.
  8. Inactive or Closed Accounts: Sending to email addresses that are no longer active or have been closed will result in bounces.
  9. Incorrect DNS Settings: Misconfigured DNS settings on your email server can cause emails to bounce.
  10. Authentication Issues: Lack of proper email authentication (SPF, DKIM, DMARC) can lead to bounces as servers reject unauthenticated emails.

Types of Email Bounces

Types of Email Bounces

Emails can bounce for various reasons, which can be categorized into two main types: hard bounces and soft bounces.

Hard Bounces

Hard bounces are permanent delivery failures and indicate that the email will never reach the recipient. Common causes include:

  1. Invalid Email Address: The email address does not exist or is incorrectly formatted.
  2. Nonexistent Domain: The domain of the recipient's email address does not exist.
  3. Blocked Email Address: The recipient's email server has blocked your email address.

Soft Bounces

Soft bounces are temporary delivery issues and may be resolved without any changes on your part. Common causes include:

  1. Full Mailbox: The recipient's mailbox is full and cannot accept new emails.
  2. Server Downtime: The recipient's email server is temporarily unavailable.
  3. Message Size: The email, including attachments, exceeds the recipient server's size limit.
  4. Greylisting: The recipient's email server temporarily rejects your email, expecting it to be resent later.

How to Calculate Email Bounce Rate

Calculating your email bounce rate is essential to monitor and improve your email deliverability. The email bounce rate is the percentage of emails that were not successfully delivered to the recipient's inbox. Here's how to calculate it:

  1. Identify Bounced Emails: Determine the number of emails that bounced in your email campaign. This information is typically provided by your email service provider (ESP) in the campaign report.
  2. Count Total Emails Sent: Note the total number of emails sent in the campaign.
  3. Apply the Formula: Use the following formula to calculate the bounce rate:
    Bounce Rate=(Number of Bounced Emails / Total Number of Emails Sent) × 100 
How to Calculate Email Bounce Rate

Example Calculation:

  • Number of Bounced Emails: 50
  • Total Number of Emails Sent: 5000

Bounce Rate=(50 / 5000) × 100

A bounce rate above 2% might indicate issues with your email list quality or delivery practices, and should prompt further investigation and corrective actions.


How to Identify a Bounced Email

Identifying bounced emails is crucial for maintaining a healthy email list and improving deliverability. Here’s how to identify a bounced email:

1. Check Bounce-Back Messages: When an email bounces, your email service provider (ESP) sends you a bounce-back message, also known as a Non-Delivery Report (NDR). This message contains information about the failure.

2. Review Email Campaign Reports: Most ESPs provide detailed reports on your email campaigns, including a section on bounced emails. These reports list the email addresses that bounced and provide reasons for the bounce.

3. Look for Specific Bounce Codes: Bounce-back messages often include specific SMTP error codes that indicate the type of bounce:

  • 5xx Codes: Indicate hard bounces, such as 550 (mailbox unavailable) or 554 (transaction failed).
  • 4xx Codes: Indicate soft bounces, such as 450 (mailbox temporarily unavailable) or 452 (insufficient system storage).

4. Analyze Email Headers: The headers of the bounced email contain valuable information about the delivery attempt. Look for fields such as “Diagnostic-Code” or “Status” to understand the reason for the bounce.

5. Use ESP Tools: Many ESPs offer tools and dashboards that automatically categorize and highlight bounced emails, making it easier to identify and address them.

6. Monitor Feedback Loops: Some ISPs provide feedback loops (FBLs) that notify you when your emails are marked as spam or bounce. Subscribing to these FBLs can help you stay informed about delivery issues.


10 Ways to Fix Your Email Bounce Back

10 Ways to Fix Your Email Bounce Back

Effectively reducing email bounces is crucial for maintaining a healthy email list and improving deliverability. Here are ten strategies to help you address and fix email bounce backs

1. Implement Double Opt-In for Email Subscriptions

Double opt-in is a method that requires new subscribers to confirm their email addresses before being added to your list. This extra step ensures that the email addresses you collect are valid and belong to real people.

How It Works:

  • A subscriber fills out your signup form and provides their email address.
  • They receive a confirmation email with a link they must click to verify their address.

Benefits:

  • Reduces Invalid Signups: Only verified emails make it to your list, reducing the risk of bounces.
  • Improves Engagement: Confirmed subscribers are more likely to engage with your content. According to Mailchimp, double opt-in lists can see engagement rates up to 20% higher than single opt-in lists.
  • Compliance with Regulations: Helps comply with email marketing laws like GDPR, which require explicit consent from subscribers.

2. Regularly Clean and Update Your Email List

Keeping your email list clean and up-to-date is essential for minimizing bounces. Over time, email addresses can become invalid or inactive, leading to higher bounce rates.

Cleaning Techniques:

  • Remove Hard Bounces: Immediately remove email addresses that result in hard bounces.
  • Monitor Engagement: Identify and remove subscribers who haven't engaged with your emails in the last 6-12 months. Campaign Monitor found that email marketers who regularly clean their lists see a 5% improvement in deliverability.
  • Use Email Verification Tools: Tools like ZeroBounce, NeverBounce, and BriteVerify can help verify email addresses before adding them to your list.

Benefits:

  • Improved Deliverability: A clean list reduces the likelihood of your emails being marked as spam.
  • Higher Engagement: Engaged subscribers are more likely to interact with your emails, leading to better campaign performance.

3. Verify and Correct Typos in Email Addresses

Typos in email addresses are a common cause of bounces. Simple errors like misspelling or incorrect domain names can prevent your emails from being delivered.

Verification Methods:

  • Real-Time Verification: Implement real-time verification during the signup process to catch and correct typos immediately.
  • Automated Tools: Use automated tools to scan your email list for common typos and suggest corrections. For example, a typo like "gamil.com" instead of "gmail.com" can be easily detected and corrected.
  • Manual Review: Periodically review your email list for any obvious typos that automated tools might have missed.

Impact:

  • Reduced Bounce Rate: Correcting typos can significantly reduce bounce rates. Experian reports that 73% of companies believe improving data quality can lead to better targeting and engagement.
  • Enhanced User Experience: Ensures that subscribers receive your emails, enhancing their overall experience with your brand.

4. Authenticate Your Email Account for Better Deliverability

Email authentication is essential for proving that your emails are legitimate and come from a verified source. It involves implementing protocols like SPF, DKIM, and DMARC to authenticate your email domain.

Key Authentication Protocols:

  • SPF (Sender Policy Framework): Defines which IP addresses are allowed to send emails on behalf of your domain. This helps prevent spoofing and phishing attacks.
  • DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails, ensuring the message has not been altered in transit.
  • DMARC (Domain-based Message Authentication, Reporting & Conformance): Provides instructions to email servers on how to handle messages that fail SPF or DKIM checks and offers feedback on email authentication status.

Benefits:

  • Enhanced Deliverability: Emails from authenticated domains are more likely to reach the inbox. According to Return Path, implementing DMARC can improve inbox placement rates by up to 10%.
  • Improved Security: Protects your domain from being used in phishing and spoofing attacks.
  • Increased Trust: Builds trust with ISPs (Internet Service Providers) and recipients, reducing the chances of your emails being marked as spam.

5. Ensure Your Content is Spam-Free

Creating spam-free content is crucial for avoiding spam filters and ensuring your emails reach the inbox. Spam filters are designed to block emails that contain certain red flags commonly associated with spam.

Content Tips:

  • Avoid Trigger Words: Words like "free," "buy now," "urgent," and excessive use of exclamation marks can trigger spam filters.
  • Balance Text and Images: Emails with too many images or links relative to the amount of text can be flagged as spam.
  • Check Spam Score: Use tools like Mail-Tester or SpamAssassin to check your email's spam score before sending. Aim for a score below 5 to avoid being marked as spam.
  • Personalize Content: Personalized emails are less likely to be marked as spam. HubSpot reports that personalized email messages improve click-through rates by an average of 14% and conversions by 10%.

Benefits:

  • Higher Deliverability: Spam-free content is more likely to bypass spam filters and reach the recipient's inbox.
  • Better Engagement: Recipients are more likely to engage with emails that are relevant and not perceived as spam.

6. Maintain Adequate Time Gaps Between Emails

Sending emails too frequently can overwhelm your recipients and lead to higher bounce rates. Maintaining adequate time gaps between emails helps ensure your messages are well-received and not marked as spam.

Frequency Management:

  • Set a Sending Schedule: Establish a regular sending schedule that respects your recipients' preferences and avoids sending multiple emails in a short period.
  • Monitor Engagement: Pay attention to engagement metrics to determine the optimal frequency for your audience. According to Campaign Monitor, the best time to send emails for most industries is mid-week and mid-morning.
  • Use Segmentation: Segment your email list based on subscriber behavior and preferences to tailor the frequency and content of your emails.

Benefits:

  • Reduced Bounce Rate: Properly spaced emails reduce the likelihood of bounces due to overwhelmed mail servers or spam complaints.
  • Improved Engagement: Recipients are more likely to engage with your emails when they are not bombarded with too many messages.
  • Enhanced Deliverability: Maintaining a healthy sending frequency helps maintain your sender reputation and improves overall deliverability.

7. Monitor and Improve Your Sender Reputation Score

Your sender reputation score is a key factor in determining whether your emails reach the inbox or are marked as spam. Monitoring and improving this score can significantly enhance your email deliverability.

Monitoring Tools:

  • Sender Score by Return Path: This tool provides a numerical score that represents your sender reputation. Scores range from 0 to 100, with higher scores indicating better reputation.
  • Google Postmaster Tools: Offers insights into your domain's performance, including spam rate, IP reputation, and domain reputation.

Improvement Tips:

  • Maintain Low Bounce Rates: Regularly clean your email list to remove invalid addresses.
  • Engage Recipients: Send relevant and engaging content to encourage opens and clicks. According to Return Path, email senders with high engagement rates can see up to 20% better inbox placement.
  • Monitor Complaints: Keep spam complaints below 0.1% to maintain a good reputation.

Benefits:

  • Better Deliverability: Higher sender reputation leads to improved deliverability.
  • Increased Trust: ISPs are more likely to trust and deliver emails from reputable senders.

8. Send Emails on a Consistent Schedule

Consistency in your email sending schedule helps build trust with both your recipients and ISPs. A consistent schedule ensures your emails are expected and welcomed by your audience.

Scheduling Tips:

  • Establish a Routine: Decide on a frequency that works for your audience, whether it’s daily, weekly, or monthly.
  • Stick to Timings: Send emails at the same time and day to create a predictable pattern.
  • Use Automation: Tools like Mailchimp and Constant Contact can automate your email campaigns to maintain consistency.

Benefits:

  • Enhanced Trust: Consistency helps build trust with your audience and ISPs.
  • Improved Engagement: Recipients are more likely to engage with emails sent at regular intervals. A study by Omnisend found that campaigns sent at consistent intervals saw 26% higher open rates and 65% higher click-through rates.
  • Better Deliverability: ISPs favor senders with consistent sending patterns, leading to improved deliverability.

9. Avoid Using Free Sender Domains

Using free sender domains like Gmail, Yahoo, or Hotmail can negatively impact your email deliverability. These domains are often associated with spammers and can lead to higher bounce rates.

Best Practices:

  • Use Custom Domains: Send emails from a domain that matches your business website (e.g., yourname@yourbusiness.com).
  • Professional Appearance: Custom domains enhance your professional image and build trust with recipients.
  • Email Authentication: Custom domains allow you to implement SPF, DKIM, and DMARC, improving deliverability.

Benefits:

  • Improved Deliverability: Emails from custom domains are less likely to be flagged as spam.
  • Enhanced Brand Image: Using a custom domain reinforces your brand and professionalism.
  • Better Engagement: Recipients are more likely to trust and engage with emails from a custom domain.

10. Stay Within Your Daily Sending Limit

Exceeding your daily sending limit can trigger spam filters and lead to high bounce rates. Adhering to your ESP’s daily sending limits ensures your emails are delivered smoothly.

Managing Sending Limits:

  • Know Your Limits: Check with your ESP to understand your daily sending limits.
  • Plan Campaigns: Schedule email campaigns to stay within limits. If necessary, stagger large campaigns over several days.
  • Monitor Sending Volume: Use ESP tools to monitor your sending volume and avoid exceeding limits.

Benefits:

  • Reduced Bounce Rate: Staying within limits helps avoid server overloads and subsequent bounces.
  • Maintained Reputation: Regularly exceeding limits can harm your sender reputation. Keeping within limits helps maintain it.
  • Improved Deliverability: Adhering to sending limits ensures smooth delivery and better inbox placement.

5 Best Tools You’ll Need to Prevent an Email Bounce

5 Best Tools You’ll Need to Prevent an Email Bounce

Preventing email bounces is crucial for maintaining a healthy email list and ensuring that your messages reach your audience. Here are five essential tools to help you prevent email bounces effectively:

1. ZeroBounce

ZeroBounce is a leading email validation and verification service designed to help you maintain a clean email list. It identifies invalid email addresses, spam traps, and abuse emails, ensuring that only valid addresses remain on your list.

Key Features:

  • Email Validation: Checks the validity of email addresses in real-time.
  • Spam Trap Detection: Identifies and removes spam traps from your list.
  • Abuse Email Detection: Flags addresses known for marking emails as spam.
  • Detailed Reports: Provides comprehensive reports on email list quality.

Benefits:

  • Improved Deliverability: By removing invalid and risky addresses, you can significantly improve your deliverability rates. According to ZeroBounce, users see an average of 98% improvement in deliverability.
  • Increased ROI: Cleaner lists lead to higher engagement and better ROI on email campaigns.

2. NeverBounce

NeverBounce is another popular email verification tool that ensures your email list is free from invalid addresses. It offers real-time verification and comprehensive list cleaning services.

Key Features:

  • Real-Time Verification: Validates email addresses as they are entered.
  • Bulk Email List Cleaning: Processes large lists quickly and accurately.
  • Integration Options: Integrates with popular email platforms like Mailchimp, HubSpot, and more.
  • Detailed Analytics: Provides insights into your email list's health.

Benefits:

  • Reduced Bounce Rates: NeverBounce users experience up to 99.9% accuracy in email validation, leading to significantly lower bounce rates.
  • Enhanced Campaign Performance: A cleaner list ensures better deliverability and higher engagement rates.

3. Mailgun

Mailgun is a powerful email delivery service that offers robust email validation and deliverability tools. It helps businesses send, receive, and track emails effortlessly.

Key Features:

  • Email Validation API: Validates email addresses in real-time and in bulk.
  • Deliverability Monitoring: Tracks email deliverability and provides actionable insights.
  • Spam Complaint Handling: Manages spam complaints and maintains your sender reputation.
  • Detailed Analytics: Offers comprehensive analytics on email performance.

Benefits:

  • Improved Sender Reputation: Mailgun's deliverability tools help maintain a good sender reputation, reducing the risk of emails bouncing.
  • Increased Engagement: Accurate validation ensures your emails reach the intended recipients, leading to higher engagement rates.

4. BriteVerify

BriteVerify is a user-friendly email verification tool that ensures your email lists are accurate and up-to-date. It provides quick and efficient validation services.

Key Features:

  • Real-Time Verification: Instantly validates email addresses as they are collected.
  • Bulk Verification: Cleans large email lists with ease.
  • Drag-and-Drop Interface: Simple interface for easy list uploads and processing.
  • Detailed Reports: Provides insights into the validation process and results.

Benefits:

  • Enhanced Deliverability: BriteVerify users report up to 98% accuracy in email validation, leading to better deliverability.
  • Cost Savings: Reducing bounce rates means fewer wasted resources and better campaign ROI.

5. Validity’s Everest

Everest, by Validity, is an advanced email deliverability platform that provides comprehensive tools for email validation, deliverability monitoring, and reputation management.

Key Features:

  • Email Verification: Ensures email addresses are valid and deliverable.
  • Deliverability Monitoring: Tracks and analyzes email deliverability metrics.
  • Reputation Management: Monitors sender reputation and provides actionable insights.
  • Inbox Placement Testing: Tests how emails perform across different email providers.

Benefits:

  • Optimized Deliverability: Everest's comprehensive tools help optimize email deliverability, reducing bounce rates and improving inbox placement.
  • Improved Campaign Performance: By ensuring emails reach the inbox, Everest users see higher engagement and better overall campaign performance.

Concluding Thoughts

Addressing email bounces is essential for maintaining a healthy email marketing strategy. By implementing these 10 effective solutions, you can significantly reduce bounce rates, improve deliverability, and enhance overall campaign performance. 

From adopting double opt-in methods and regularly cleaning your email list to authenticating your email account and using professional tools like ZeroBounce and Mailgun, each step plays a crucial role. Prioritizing these strategies will ensure that your emails reach their intended recipients, helping you build stronger relationships and achieve better results in your email marketing efforts.

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