Bounce Back: The Complete Guide to Preventing and Handling Email Bounces

Have you ever felt the frustration of an email bouncing back instead of reaching the intended recipient’s inbox? While bounce backs are unavoidable, you can minimize how often they happen and handle them properly when they do occur. This comprehensive guide will show you how to achieve excellent email deliverability by understanding the causes of bounces, calculating bounce rates, following best practices, and leveraging bounce data to strengthen your overall strategy. Master email bounce management and say goodbye to return-to-sender notifications for good.

Page Contents

What is an Email Bounce?

Sending emails is an integral part of most businesses today. Whether you’re reaching out to potential customers with promotions, connecting with existing clients, or communicating internally, email remains one of the most ubiquitous communication channels.
But have you ever sent an email that just didn’t seem to reach its intended recipient? Instead of arriving safely in the inbox, it bounced right back to you.

This strange phenomenon is known as an “email bounce” – and it can happen for several reasons. Keep reading to understand exactly what email bounces are, the different types, how to recognize bounce messages, and implications for your email strategy.

Defining an Email Bounce

When an email “bounces”, it means the message was rejected or unable to be delivered to the recipient’s inbox. Essentially, the email “bounced off” the receiving server and returned to the sender.

Bounces occur due to something preventing delivery on either the sender’s or recipient’s end. You may encounter temporary bounces that resolve themselves. But hard bounces indicate a permanent delivery failure that requires action to fix.

Here’s a useful analogy – think of sending a physical letter by post. If the recipient’s address doesn’t exist, the letter gets returned to your mailbox. Email bounces function similarly.

Soft Bounces vs Hard Bounces

There are two main categories of email bounces: soft and hard. The implications and fixes differ for each, so it’s important to know how they vary:

Soft Bounces

A soft bounce is a temporary failure that prevents email delivery. Some common triggers for soft bounces include:

  • Recipient’s inbox is full
  • Mail server downtime
  • Server overloaded
  • Message too large

With a soft bounce, the recipient’s email address itself is still valid. Once the underlying issue is resolved, messages can be delivered normally again. Soft bounces don’t harm your sender reputation.

Hard Bounces

Hard bounces are permanent delivery failures due to invalid or non-existent recipient addresses. For instance:

  • Incorrect email address syntax (e.g. misspellings)
  • Closed email accounts
  • Non-existent domains

With an invalid recipient address, sending the email again won’t help because the error is fundamental. Hard bounces can negatively impact your sender rating if left unchecked.

Identifying Bounce Notifications

When an email bounces, you’ll receive an automated notification explaining the failure along with details like:

  • The original message’s date, recipients, subject line
  • Error code and description
  • Severity (hard vs soft bounce)
  • Troubleshooting tips

These notifications come in the form of Non-Delivery Report (NDR) messages, also called bounce messages.

Here’s an example NDR:

Hi Sender, 

Your message could not be delivered to:

[email protected]

Original message details: 
Date: March 3, 2023
Subject: Promotion Alert

Error Code: 553-Address rejected 

The email address you tried to reach does not exist. Please check for any typos or spelling errors. This recipient cannot be reached.

Hard vs soft bounces are distinguishable by their error codes. Codes starting with 5 (like 553 above) indicate a hard bounce. 4xx codes are soft bounces.

Carefully reviewing these notifications helps diagnose what went wrong so you can take corrective actions.

Why Do Bounces Matter?

While the odd bounce here and there is no cause for concern, high overall bounce rates can negatively impact your sender reputation and email deliverability over time.

When servings see high volumes of mail continuously bouncing, they may:

  • Throttle send rates from your IP address
  • Apply extra spam filtering to your mail
  • Blacklist your domain

Additionally, bounces waste your time and resources contacting nonexistent or invalid emails. That’s why keeping bounce rates low ensures your messages reliably reach recipients and avoids harming your sender score.

In summary, email bounces occur when delivery to the recipient fails and messages get rejected. Soft bounces are temporary hiccups, while hard bounces require address fixes before resending. Carefully managing bounces protects your sender reputation so that your emails reliably land in inboxes.

Why Do Emails Bounce?

Now that you know what email bounces are, you may be wondering – why exactly do they happen in the first place?
There are a variety of potential triggers causing emails to get rejected or bounce rather than reaching the intended recipient. Understanding these root causes is key to preventing bounces.

Let’s explore the main reasons your outgoing emails may hit snags and bounce back before being delivered:

1. Invalid or Mistyped Email Addresses

One of the most common bounce causes is simply an incorrect email address. With manual data entry, it’s easy for typos or formatting mistakes to creep in:

Hard bounces result when sending to completely invalid addresses. Before uploading lists, use email verification tools to catch any faulty addresses.

2. Inactive Email Accounts

If the recipient’s email account has been closed or disabled, your message will hard bounce because that address no longer exists.

People change jobs or providers, leaving old accounts inactive. Over time, addresses get abandoned, causing a growing fraction to bounce.

Purchased email lists are particularly vulnerable to inactive data. Rented lists have up to 35% fake or obsolete addresses. Always opt for first-party permission-based lists.

3. Full Mailboxes

Has the recipient hit their inbox size limit? When someone lets their account become bloated with thousands of unread messages, new mail may bounce back due to a full mailbox.

This overfilled state produces soft bounces that continue until space is freed up. Offer subscribers options to unsubscribe if they aren’t reading your content.

4. Blocked Senders

Certain recipients may intentionally block your emails at an ISP level. For instance, commercial addresses are sometimes preemptively blocked for suspected spam.

Ask recipients to whitelist your sending domain or IP address. Switching to a dedicated IP and warming it up properly helps avoid blocks.

5. Server Issues and Limitations

Receiving servers may reject mail due to downtime, overloaded queues, or hitting configured size limits:

  • Server offline: System downtime or maintenance at the recipient’s domain will lead to soft bounces until operations resume.
  • Too much volume: If an email server is inundated with excess traffic, it may bounce new messages when queues build up. Spreading campaigns over time avoids overloading servers.
  • Size constraints: Recipient servers enforce maximum email sizes they will accept. Oversized messages get bounced back. Compress images and attachments to optimize message size.

As the sender, these service problems are out of your control. But being aware helps handle the resulting bounces appropriately.

6. Spam Filters

Aggressive spam filtering is another common source of emails bouncing before reaching the inbox. Filters aim to protect recipients by identifying unsolicited, dangerous, or low-reputation mail.

But legitimate marketing messages can also get flagged as spam if certain red flags are triggered:

  • Spammy words: Terms like “Act Now!” and “Free Trial” can be blacklist triggers leading to bounces. Avoid hype and cliches.
  • Suspicious links: Embedded links set off alarms if they use link shorteners or point to bad neighborhoods on the web. Host landing pages on your official branded domain.
  • Relevancy: Irrelevant content or subject lines increase spam risk if recipients don’t recognize your brand. Personalize messages and segments.

Optimizing email formatting and content for each recipient minimizes false spam filtering.

Now let’s examine the specific root causes behind hard vs soft bounces in more depth.

Hard Bounce Causes

Hard bounces occur when the recipient address itself is invalid or deactivated. Typical hard bounce triggers include:

Non-Existent Email Addresses

  • Incorrect email syntax (e.g. misspellings, typos)
  • Made-up or fabricated addresses

Disabled or Closed Accounts

  • Recipient changed providers or left company
  • Old email lists contain outdated data

Invalid Domains

With a fake, mistyped, or outdated email, resending the message won’t fix the fundamental address error. That’s why hard bounces require removing the faulty addresses from your lists.

Soft Bounce Causes

In contrast, soft bounces are temporary hiccups where the recipient address itself remains valid and active. Common soft bounce reasons include:

Full Inboxes

  • Recipient exceeded storage quota
  • Too many unread messages

Server Downtime

  • Planned maintenance or upgrades
  • Unexpected outages or crashes

Message Size Limits

Soft bounces resolve once the condition is cleared. The recipient address still functions, so you can reattempt delivery after some time.

Isolating the unique factors causing your emails to bounce is the crucial first step. Then you can match smart solutions to each scenario for reducing bounces and improving email deliverability.

Bounce Case Study: Anatomy of a Hard Bounce

Let’s walk through a real-world example illustrating what a hard bounce looks like.

John Doe works for ACME Company and needs to email his latest sales presentation to a prospect at [email protected].

He crafts the message through his company email marketing platform and clicks send. But two hours later, John receives an undeliverable notification:

Hi John, 

Your message to [email protected] could not be delivered due to an invalid recipient address. See details below:

Original Message: 
To: [email protected]
Date: August 1, 2022 
Subject: ACME Sales Presentation

Status: 550 Permanent Failure 
Diagnostic Code: 5.1.0 Unknown address error

The domain does not exist. The email address you sent this message to is invalid. Please verify the recipient's address and resend your email.

This error clearly indicates a hard bounce. The domain is fabricated, making the email address nonexistent.

John realizes he must have accidentally typed the domain when adding potentialclient to his outreach list. He removes the errant address and reaches out to confirm the prospect’s real email before sending again.

This is a textbook case of a hard bounce situation. Without a valid domain and mailbox, the message permanently fails. By following up to correct the mistaken address data, John can avoid repeating this bounce scenario.

Carefully checking bounce error notifications allows senders like John to pinpoint what went wrong and take appropriate action.

Soft Bounce Case Study: When Servers Struggle

Soft bounces can be trickier to diagnose compared to obvious hard bounces. Let’s walk through an example soft bounce scenario.

Marketing manager Anne intends to deliver the company’s latest promo email to their house list of 10,000 subscribed customers. She presses send Friday afternoon right before leaving work.

Over the weekend, Anne receives a smattering of bounce notifications like this:

Hi Anne, 

Your message to [email protected] could not be delivered due to a temporary issue with the recipient server. See details below:  

Original Message:
To: [email protected]
Date: March 5, 2022
Subject: 15% Off This Weekend!

Status: 421 Server temporarily unavailable  

The server for is experiencing technical difficulties and is unable to receive new messages at this time. Please retry delivery later once service is restored.

Come Monday morning, Anne checks the full campaign report revealing a slightly elevated soft bounce rate of 1.8% compared to the usual 1.5%. Manyrecipients with addresses bounced due to server trouble.

After contacting Example Co’s IT department, Anne confirms over the weekend they performed system maintenance causing temporary outages. By Tuesday, service and deliverability returned to normal.

This demonstrates a classic soft bounce situation. The recipient domain and addresses were valid the whole time. The transient server downtime prevented delivery temporarily before resolving.

As the sender, no further action is required beyond monitoring soft bounces to ensure they dissipate as expected.

Understanding the myriad of reasons emails bounce helps maximize deliverability. Whether it’s fixing flawed addresses, avoiding spam filters, or handling server hiccups, properly managing bounces keeps your messages out of the dead letter office and safely in subscriber inboxes.

How to Calculate Your Email Bounce Rate

Now that you understand why emails bounce, how prevalent are bounces for your own emails? Determining your overall email bounce rate provides crucial insights.
Calculating your bounce rate helps benchmark deliverability and identify issues needing attention. In this guide, we’ll cover:

With this knowledge, you can accurately determine your current bounce rates and take steps to reach healthier levels.

Bounce Rate Formula

Your email bounce rate represents the percentage of sent messages that get rejected or bounced, rather than reaching recipients’ inboxes.

To calculate it, divide your total number of bounce notifications by the total emails you attempted to send.

Bounce Rate = (Bounced Emails / Total Sent Emails) x 100

For example, if you sent 20,000 emails last month, and 400 bounced back, your bounce rate would be:

(400 / 20,000) x 100 = 2%

This basic formula works for individual campaigns or overall historical sending. Just plug in the time range’s totals to determine bounce prevalence.

Acceptable Bounce Rate Thresholds

So when should your bounce rate start raising red flags? Industry experts consider under 2% to be a healthy rate for most business mailing lists.

According to ReturnPath’s data, the average commercial bounce rate is around 0.64%, or 6 bounces per thousand emails sent.

For reference, here are typical bounce rate benchmarks by major industry:

  • Retail – 0.58%
  • Technology – 0.71%
  • Media/Publishing – 0.80%
  • Nonprofits – 0.57%

Aim to keep your own bounce rate within 0-2%. Rates climbing above 3% indicate potential issues requiring bounce management triage.

Factors Impacting Your Bounce Rates

Many variables influence bounce rates, including:

  • Email list quality – Good list hygiene means lower bounces. Letting flawed, outdated addresses linger inflates bounces.
  • Sending frequency – Occasional messages have lower bounce rates than daily mailings. Spreading volume over time helps.
  • List type – Opted-in lists have far fewer bounces than purchased or rented email lists. Prioritize first-party contacts.
  • Email type – Transactional mailings tend to bounce less than cold outreach or sales emails from unfamiliar senders.
  • Subscriber engagement – Low open and click rates accompany higher bounce rates, signalling disengaged recipients.

Regularly monitoring bounce rates segmented by these categories of factors pinpoints where issues arise. Delve deeper into elevated bounce clusters and geographic regions to troubleshoot.

Tracking and Monitoring Bounce Rates

To optimize your bounce rates, real-time monitoring and analytics are essential. Here are proven techniques for keeping tabs on bounces:

Use Email Analytics Software

Robust email service providers have built-in tracking of bounces, complaint rates, blacklist status, and other key metrics.

For instance, Constant Contact’s bounce summary shows bounce types by campaign and contact category. This informs cleanup actions like removing hard bounces.

Understand Bounce Reports

Digging into detailed bounce reports reveals why emails are getting rejected. Analyzebounce reasons, domains, addresses, and timestamps.

Isolate spikes to identify situational soft bounces versus consistent hard bounces needing permanent removal.

Log Bounce Details

For ongoing optimization, record bounce specifics – date, email, cause, type, etc. Tracking bounce history over time provides vital diagnostics.

Use this intel to continually fine-tune your processes around hygiene, sending practices, content, timing, and troubleshooting.

With careful bounce rate monitoring and analysis, you gain visibility to diagnose issues and cultivate improved email deliverability.

Email Marketing Strategies to Reduce Bounces

If your current bounce rates need improvement, here are four proven tactics to consider:

1. Confirm Opt-Ins

Ensure all list members actively opted in and confirmed their subscription. This minimizes nonexistent or unresponsive addresses.

2. Upgrade Email Infrastructure

Investing in dedicated IPs and high-quality email service providers enhances reputation and deliverability.

3. Personalize Content

Sending targeted, relevant messages avoids false spam flags. Tailor subject lines, offers, and creative per recipient.

4. Automate List Hygiene

Maintenance tasks like removing stale addresses are easily automated based on activity and bounce history.

Getting bounce rates within acceptable norms takes work but pays dividends long-term in your sender reputation and open rates.

How to Prevent and Reduce Email Bounces

Now that you understand why emails bounce and how to diagnose your bounce rates, it’s time to prevent future bounces.
With the right combination of email hygiene, sending practices, and system optimizations, you can achieve lower bounce rates and happier customers.

Here are proven techniques for reducing email bounces:

1. Maintain Clean Email Lists

The quality of your mailing lists is the #1 factor influencing bounce rates. List hygiene is essential for email success.

  • Remove hard bounces promptly – Delete permanently failed addresses that will just bounce again. Use email verification tools to preemptively clean lists.
  • Suppress soft bounces – Temporarily stop mailing to soft bounced addresses until they recover, to avoid repeat bounces.
  • Delete inactive subscribers – Review engagement metrics and remove long-time inactive or unsubscribed members.
  • Update subscriber details – When contacts change jobs or email addresses, update their info to avoid obsolete data. Allow list updating via subscription forms.
  • Scrub regularly – Make list cleaning a recurring routine. The longer you delay hygiene, the more bounces accumulate.

Well-tended lists reduce bounces, increase security, and improve open rates.

2. Validate Addresses Before Sending

Double check email addresses are valid and accurate before hitting send. For manual uploading or entering data, it’s easy for typos or formatting mistakes to slip in.

  • Visual inspection – Eyeball samples to catch blatant errors like “” or blank cells.
  • Verification tools – Services like ZeroBounce and NeverBounce validate syntax and confirm mailboxes exist, before you import lists.
  • Confirm opt-ins – Ensure all list members actively opted in and verified their subscription via confirmation emails.

Validating addresses upfront identifies issues before they trigger bounces. This protects your sender reputation, while optimizing list quality.

3. Manage Spam Complaints

Even if your content isn’t deliberately spammy, recipients sometimes report emails as spam by accident. Too many spam flags negatively impact deliverability.

  • Unsubscribe promptly – Honor all unsubscribe requests within 3 business days to avoid spam complaints.
  • Send valuable content – Subscribers are less likely to mark truly useful mailings as spam. Offer personalized value.
  • Avoid spammy formats – Overusing ALL CAPS, bold text, images, or hype language can trigger spam filters.

Proactively managing complaints keeps your sender reputation intact despite occasional false spam reports.

4. Follow Best Practices for Emails

Beyond list hygiene, meticulously crafting email content and infrastructure also reduces bounces.

  • Personalize subject lines – Recipient names and context build trust and increase opens. Avoid spammy urgency like “ACT NOW”.
  • Match content to recipients – Relevancy minimizes false spam flags. Segment and tailor messaging.
  • Send from proper domains – Use your official company domain rather than generic ESP addresses. Authenticate domains with SPF/DKIM.
  • Link to your website – Host landing pages on your primary site to increase trust when clicked. Avoid link shorteners.
  • Compress images – Bulky graphics can exceed size limits. Resize and compress pictures for faster loading.

Email formatting directly impacts spam filtering and inboxing rates. Optimizing content presentation goes a long way.

5. Use Dedicated IP Addresses

Shared IPs have higher bounce rates and spam risks, since the reputation depends on the whole shared group’s behavior not just yours.

Upgrading to dedicated IPs for sending gives you full control over inbox deliverability through:

  • Pristine IP reputations – Fresh dedicated IPs have no usage history yet when first provisioned.
  • Total sending control – Unlike with shared IPs, no other ESP tenants can jeopardize your email reputation.
  • Warmup flexibility – New IPs must be gradually warmed up to avoid mass mailing rate limits. Dedicated IPs allow proper warmup pacing.
  • Lower abuse potential – Accounts with bad sending habits get isolated from yours when using distinct IPs.

Despite higher costs, dedicated IPs are worthwhile for serious email senders concerned with deliverability.

6. Monitor Your Sender Reputation

To preempt issues impacting bounce rates, closely monitor your domain and IP reputation. Receiving servers rely heavily on sender reputation to gauge trust and spam risk.

Watch for warning signs like:

  • Sudden spikes in spam complaints
  • Being blacklisted by major ISPs
  • New sending limitations or blocks imposed

Catching reputation dips early allows swift corrective action before deliverability degrades further. Sender score monitoring tools like SenderPulse provide alerts.

Fixing Invalid Addresses

Despite best efforts, some bad addresses inevitably slip through causing hard bounces. Here are remediation tips:

Use Email Verification Services

Address validation services like ZeroBounce automatically verify data file correctness before uploading lists. This flags typos, disposable emails, syntax errors, and other unreliable addresses.

Upfront error checking avoids needless hard bounces once sending commences.

Require Double Opt-In

Double opt-in confirms subscribers meant to sign up by making them verify email addresses after submitting forms. One-click opt-ins often have higher fake or unmonitored addresses.

Double opt-in reduces hard bounces by around 50% versus single opt-in.

Promptly Remove Hard Bounces

Once identified, immediately delete hard bounced addresses rather than pointlessly resending to the same invalid mailbox.

Regularly clearing hard bounces protects your sender score. But make sure contacts aren’t simply out on vacation before removing.

Invalid addresses trigger hard bounces. Being proactive prevents their accumulation.

Avoiding Spam Filters

Optimizing email content and practices minimizes false spam flags leading to blocks or bounces:

Send Only Permission-Based Mailings

Don’t buy or rent email lists. Spam filters scrutinize unknown senders closely. Prioritize only first-party opt-in contacts.

Avoid Spam Trigger Words

Watch for filter blacklisted terms like “Free”, “Deal”, “Limited Time”, “Act Now” and excessive repetition of words.

Personalize Content

Generic blasts get flagged more readily than emails using custom recipient details. The more relevant your messaging, the better.

Proactively engaging subscribers and crafting context-aware content keeps your emails out of the spam box.

Optimizing Your Sending Process

Fine-tuning technical email delivery details also reduces bounces:

Use a Consistent Sender Identity

The “From” name, domain, and address should remain constant across campaigns. This establishes recognition and trust.

Keep Email Sizes Reasonable

Avoid giant attachments and image-heavy HTML bloating message size.

Properly Warm Up New IP Addresses

When switching ESPs or procuring new dedicated IPs, gradually ramp up volumes, don’t abruptly blast at full speed. Follow warmup guidance to avoid mass rejections.

Spread Volume Over Time

Distribute large campaign blasts over multiple smaller sends separated by days or hours. Don’t overwhelm recipient servers in one huge barrage.

Email infrastructure optimizations and smart sending practices avoid instigating bounces in the first place.

Ways to Confirm Opt-Ins and Get Valid Addresses

While email verification services help identify issues in existing lists, preventing bad addresses upfront is ideal.

Here are six methods for confirming genuine user opt-ins to build quality lists from scratch:

1. Require confirmed sign ups

New subscribers verify through confirmation emails. This filters out fake or typo-ridden addresses entered on web forms.

2. Incentivize for business purposes

A coupon or discount for joining your list ensures contacts share correct addresses to redeem offers.

3. Tie to purchases

Associate sign ups with buying from your ecommerce storefront to capture genuine customer addresses.

4. Gate premium content

If you produce reports, webinars or other assets, require subscriptions to access them.

5. Promote at live events

Collect in-person signups by promoting your mailing list at conferences or meetings.

6. Integrate with social platforms

Allow opt-ins via already verified social media profiles like Facebook or LinkedIn.

Building your list from real people intrinsically engaged with your brand ensures address validity.

How Leading Email Service Providers Handle Bounces

Top-tier email service providers offer robust features to automate bounce management:

  • Automatic bounce processing – Instantly remove hard bounces and retry soft bounces.
  • Bounce categorization – Log and classify bounce types for cleanup.
  • Bounce alerts – Provide notifications when thresholds are exceeded.
  • List hygiene – Auto-suppress inactive subscribers and complainers.
  • Reputation monitoring – Track IP and domain sender score.
  • Open rate optimization – Ensure inboxes by identifying engaged subscribers.
  • Infrastructure controls – Provide dedicated IPs with proper warmup.

Leveraging ESP bounce automation handles tedious list maintenance work so you can focus on creating content.

Carefully crafting emails, maintaining list hygiene, fine-tuning sending practices, and selecting the right ESP combined create a solid bounce management foundation.

Mastering bounce prevention safeguards your deliverability. Recipients enjoy uninterrupted email access. And your business benefits from reputable inbox placement driving sales and growth.

Bounce Management Best Practices

Now that you know how to minimize email bounces, effective bounce management ensures any that do occur are handled properly.
Turning bounce insights into process improvements will keep your inbox delivery on target. Follow these bounce management best practices:

Auto-Removal of Hard Bounces

Hard bounces indicate permanently failed addresses that will only bounce again. Promptly deleting these avoids wasted sending.

  • Enable auto-cleanup – ESPs like SendGrid can automatically remove hard bounces saving you manual work.
  • Review weekly – If auto-cleanup isn’t enabled, diligently review weekly hard bounce reports and delete those addresses.
  • Update your records – Suppress hard bounced addresses in your CRM or marketing automation systems to halt further contacts.

Removing hard bounces protects metrics and ensures you aren’t futilely emailing invalid inboxes.

Periodically Clear Soft Bounces

Soft bounces are temporary, but may still accumulate and distort bounce rates if never addressed.

  • Give time to rectify – Initially pause sending to allow the ISP or user issue to resolve on its own.
  • Review monthly – Check soft bounce logs monthly. Suppress any addresses consistently bouncing for 60+ days despite reattempts.
  • Segment intelligently – Don’t blanket remove all soft bounces. Assess the root cause of each before taking action.
  • Try re-engaging – If high-value recipients have soft bounced, attempt to re-engage them via other channels first before removing.

With care taken, temporary soft bounces can revert to successful delivery avoiding unnecessary unsubscribes.

Update Contact Records

Sync your email service provider’s bounce data back to your primary contact records, like your CRM platform.

  • Import bounce logs – APIs allow automated bouncing reporting into your subscriber CRM profile records.
  • Segment effectively – When importing bounce info, distinguish between hard vs. soft bounces within your main subscriber profiles.
  • Halt other outreach – Suppress both emails and non-email contacts like calls or direct mail for hard bounced addresses.

By centralizing bounce status across channels, you prevent wasted efforts and communicate better cross-channel.

Send Follow-Up Messages

If emails start bouncing suddenly to previously solid addresses, special nurturing helps re-engage recipients.

Send follow-up messages via:

  • Personalized email checking on them
  • Phone call to update contact info
  • Postcards or letters to confirm status
  • Social media outreach on Twitter/Facebook

This extra effort for VIP bouncers can uncover address changes to get them successfully re-subscribed. Treat your list with TLC.

Leverage Email Service Providers

Robust ESPs like Omnisend include automation to handle tedious bounce chores:

Built-in Bounce Handling

Native bounce processing automatically removes hard bounces and temporarily suppresses soft bounces based on rules you set.

Automated List Cleaning

Schedule periodic jobs to automatically prune inactive subscribers, non-openers, and those with stale bounce data.

Bounce Alerts and Notifications

Receive real-time bounce alerts when thresholds are exceeded so you can handle issues promptly.

List Segmentation

Built-in segmentation makes subgroups like bouncers easy to isolate for dedicated follow-up messages.

Leaning on ESP bounce tools lightens the workload so you focus on creating content subscribers love.

Fixes to Salvage Engaged Bouncers

Not all bounces require immediate list removal. For valued subscribers temporarily bouncing, rescue strategies like these retain them:

1. Send to an alternate email

If you have a secondary address on file, update their profile and send there instead while their main inbox recovers.

2. Call or mail personally

Hearing directly from you keeps these VIP contacts engaged despite email hiccups.

3. Resend once issues resolve

Monitor when the problem clears up, then proactively resend your last few emails to bring them up to speed.

4. Provide “email preferences” options

Allow recipients to easily update email addresses themselves by embedding subscription management links.

With personal care, temporary bouncers transform into re-activated loyal brand advocates.

How Nonprofits Optimized Bounce Management

As a case study, examining how nonprofits tackle bounce management provides real-world inspiration:

  • Scheduled hygiene – Oxfam automatically scrubs lists of lapsed donors quarterly to eliminate stale addresses. This yielded a 25% reduction in bounce rates.
  • Triggered deletion – After Greenpeace instituted a rule to automatically purge emails after 3 consecutive daily bounces, their hard bounce rate declined from 1.5% to under 0.5%.
  • Reconfirmation campaign – The Red Cross periodically asks subscribers to reconfirm opt-in status via dedicated repermission campaigns. This confirms who remains actively engaged.
  • CRM tracking – Charity:Water integrates bounce data from their ESP into donor CRM records, stopping not only emails but also direct mail and phone outreach to bad addresses.

With bounce management disciplines in place, charities enjoy cleanly segmented lists and the highest inbox placement effectiveness to maximize donations.

Carefully handling bounces in a CRM-integrated approach futureproofs your email performance. Staying on top of list hygiene helps emails bounce safely to recipients’ inboxes rather than back to you.

Using Bounces to Improve Your Strategy

Rather than seeing bounces as just a nuisance, clever marketers transform them into opportunities to enhance their overall email strategy.
Bounce insights help segment better, try new approaches, and strengthen engagement. With some creative thinking, bounces provide a silver lining.

Identify Inactive Subscribers

Bounces indicate which subscriber addresses are outdated, abandoned, or no longer being used. Flagging these for removal or re-engagement improves list quality long-term.

Reviewing historical bounce trends reveals subscriber cohorts to prioritize:

  • New contacts bouncing at higher rates hint at lead gen process weaknesses.
  • Bounces concentrated in certain regions may indicate ISP deliverability issues.
  • Customers bouncing months after purchase date may warrant winback outreach.

Isolate segments driving elevated bounce rates, then tailor copy and content accordingly.

Find Flawed Data or Processes

Recurring bounces exposing the same pain points imply opportunities to improve systems.

  • Repeated typos –> Update opt-in forms to validate addresses
  • Frequent full inboxes –> Increase cadence of mailbox cleaning reminders
  • High blocked domain rates –> Guide recipients through whitelisting
  • Persistent spam complaints –> Refine copy to avoid filter trigger words

Let bounce patterns show you where workflows, templates, and tools need refinement.

Refine Outreach Targeting

The attributes of bounced addresses when analyzed help sharpen your targeting.

  • Bounce rates by geography, role, or industry reveal which prospect segments have higher data decay.
  • Seeing higher engagement from competitors’ domains versus yours indicates potential targeting upside.
  • Reviewing bounce timing can identify optimal messaging windows, like following up 6 months post-purchase rather than 12.

Segment all campaign metrics by bounce rate to pinpoint better recipient targeting.

Test New Content and Offers

Use A/B testing to experiment with content and improve results among customers with elevated bounce history.

  • For repeat bouncers, try more benefit-driven subject lines versus promotional ones.
  • If several industries bounce more, craft industry-specific content and offers tailored to their needs.
  • Test email only nurturing tracks versus omnichannel ones for bounced lapsed customers.

Bounces indicate an opportunity to try new approaches and see what resonates.

Tips to Learn from Your Bounces

Bounce analytics offer myriad lessons for strengthening email strategy. Here are five proven ways to let bounce data guide decisions:

1. Correlate bounce rates to engagement metrics

High bounce segments likely suffer lower open and click-through too. Review bounce data layered on top of engagement metrics to identify high-risk groups.

2. Monitor trends over time

Assess bounce rate trajectory month over month. Spikes or new patterns may require investigation before they worsen.

3. Compare bounce locations

Review bounce density across regions, industries, company sizes, or other contact variables. Any disproportionate pockets warrant tailored action.

4. Review by list source

Breakdown bounce rates for contacts acquired from webinars, events, referrals, etc. The higher the rate from a source, the more scrutiny it needs.

5. Look for double bouncers

Recipients bouncing repeatedly signal deeper issues to address. Bounce recurrence frequency shows who needs priority care.

Treat bounce intel like a vital health check of your email program. Diagnose issues early before they escalate.

Hypothetical Case Study

Let’s walk through a fictional example showing how proactive bounce analysis improved email results:

SaaS startup Uplift’s head of marketing, Amanda, reviews bounce rate reporting weekly.

She notices bounce rates among freemium trial users double month-over-month from 2% to nearly 4%.

Digging deeper, she segments bounce rates by trial signup source. Amanda sees referrals from their Facebook ads bounce 30% more than webinar referrals.

To test improvements, Amanda changes trial confirmation emails sent to Facebook referrals to be:

  • Simpler with less jargon
  • Emphasizing Uplift’s core value proposition
  • Sent twice weekly rather than just post sign-up

Confirmations for webinar referrals remain unchanged as the control.

Over the next month, Amanda finds:

  • Bounce rates for Facebook referrals decrease to the webinar levels
  • Click-through rates on confirmation emails rise 5X
  • Trial start rates grow 20% for Facebook referrals

By acting on bounce insights, Amanda optimized both deliverability and engagement for a key segment.

Rather than ignoring bounces, leverage them to actively strengthen your email marketing performance. Get tactical with your bounce back strategy.


Bounced emails are a reality every sender must contend with. But mastering bounce management helps maximize email deliverability.
Now you have a comprehensive understanding of what causes emails to bounce and how to minimize their impact. Let’s recap the key takeaways:

  • Monitor bounce rates – Carefully track your overall bounce percentages and segment rates by campaign, source, geography and other attributes. Measure against industry benchmarks.
  • Understand bounce types – Categorize bounces as hard (permanent failures) or soft (temporary). This determines appropriate next steps.
  • Review notifications – Analyze bounce messages to pinpoint why emails are getting rejected and what needs fixing.
  • Keep lists clean – Proactively purge invalid addresses, inactive subscribers and complainers. Preventing bad data is most effective.
  • Optimize sending practices – From thoughtful content to reasonable email sizes and volumes, optimize your approach.
  • Leverage tools – Email verification services, duplicate checkers, and built-in ESP bounce handling provide efficiency.
  • Stay vigilant – Make bounce management an ongoing priority through list hygiene, process reviews, and strategy optimization.
  • Go granular – Slice bounce data many ways – by campaign, source, content, timing, demographics etc. Look for patterns.
  • Experiment – Use A/B testing to figure out what content and segmentation appeals most to historically high bouncing segments.

With a sharp focus on bounced email best practices, your inbox placement and engagement metrics will continue trending upward.

Key Takeaways: Preventing and Handling Email Bounces

  • Email bounces occur when delivery to the recipient fails, causing the message to “bounce back” to the sender. Soft bounces are temporary while hard bounces are permanent.
  • Invalid addresses, inactive accounts, full inboxes, blocked senders, spam filters, and server issues cause bounces. Review notifications to understand the root cause.
  • Calculate your overall bounce rate by dividing bounced emails by total sent emails. A rate below 2% is ideal for most senders.
  • Minimize bounces by confirming opt-ins, list cleaning, address verification, proper email formatting, and dedicated IPs.
  • Manage bounces through promptly removing hard bounces, following up with soft bounces, updating contact records, and leveraging ESP tools.
  • Learn from your bounce data by correlating metrics like engagement, analyzing trends, and testing new approaches with high bounce segments.
  • Consistent list hygiene, bounce monitoring, email best practices, and continuous optimization ensure excellent deliverability over time.

FAQs About Email Bounces

Given email bounces are so common, many frequently asked questions arise. Let’s explore top bounce-related queries:

What is a bounce back message?

A bounce back message, also called a non-delivery receipt (NDR), is an automated notification sent to the email’s sender when delivery fails.

It typically includes details like:

  • Original message date, subject, recipients
  • Reason for the bounce
  • Error code and description
  • Severity of bounce (hard vs. soft)

Reviewing bounce backs helps diagnose and address delivery issues.

How long do bounced emails stay in inbox?

Bouncebacks are usually received within minutes or hours of the original send attempt. However, delays can occur:

  • Immediate bounces: Invalid addresses trigger instant bounces. These happen at the point of handoff between email servers.
  • Transient bounces: Soft bounces from temporary issues deliver in minutes or hours once retry attempts expire.
  • Delayed bounces: Some ISPs hold messages for up to 4 days before bouncing to allow the recipient time to recover space if over quota.

Most bounce backs fire within a day. But allow up to a week before assuming a sent email was delivered, if no bounce received.

Can I resend an email that bounced?

You can reattempt delivery on soft bounced emails after the cause resolves. However, hard bounced messages should not be resent to the same address.

Be sure to review bounce error notifications to understand the root cause before resending:

  • Hard bounces mean the address is permanently invalid. Sending again will keep bouncing. Remove these addresses instead.
  • Soft bounces imply a temporary obstacle like full inbox or unavailable server. Once the blockage clears, resending may land successfully.
  • Spam complaints should also not be resent to avoid further complaints. Remove or nurture these contacts through other means.

Why am I getting bounced emails I sent?

There are several potential reasons your sent emails start bouncing back to you:

  • Recipient address is mistyped or invalid (hard bounce)
  • Recipient inbox is full (soft bounce)
  • Recipient server is down (soft bounce)
  • Message is blocked by recipient’s ISP (soft bounce)
  • Message marked as spam by recipient (soft bounce)

The bounce back notification should specify the exact reason for the delivery failure.

How do I stop receiving bounced emails?

To minimize future bounces:

  • Promptly remove invalid addresses triggering hard bounces
  • Resolve soft bounce causes like server outages
  • Adjust sending practices to avoid false spam flags
  • Clean your list regularly to delete old addresses
  • Only send wanted content to engaged subscribers

Of course periodic bounces will still occur. But disciplined bounce management reduces their frequency.

FAQs About Hard Bounce Emails

Hard bounces warrant extra attention due to their permanent nature. Common questions include:

Why do hard bounces happen?

Hard bounces occur when the recipient address is invalid and message delivery fails permanently. Common causes include typos, closed accounts, invalid domains, or unknown users.

What’s the difference between hard and soft bounces?

Hard bounces are permanent delivery failures and can’t be fixed by simply resending. Soft bounces are temporary issues like full inboxes where messages may still get delivered later.

What should I do when an email hard bounces?

Remove the faulty email address from your contact list. Sending future emails to it will keep bouncing. Also update associated CRM records to stop contacting that address.

How do I prevent hard bounces?

Upfront email list cleaning identifies bad addresses before sending campaigns. Confirm opt-in and regularly purge stale addresses causing bounces.

Can I tell if an email bounced before sending?

Yes, email validation tools like ZeroBounce and NeverBounce can preemptively identify addresses likely to hard bounce due to issues like typos, spam traps, and invalid syntax.

How often should I clean my list to remove hard bounces?

Ideally, cleanup your lists at least quarterly. Monthly is better for senders with large volumes. Promptly deleting hard bounces when they occur is good practice.

What else can cause a message not to reach the recipient besides a hard bounce?

Besides invalid addresses causing hard bounces, messages may fail to be delivered if they get flagged as spam, blocked by a recipient ISP, filtered by an overly strict server, or soft bounced by a full inbox.

Careful attention to hard bounces ensures your emails reliably reach inboxes rather than hitting dead ends. Addressing frequently asked bounce questions equips you to maximize email deliverability.

Other Frequently Asked Questions About Email Bounces

What is an email bounce?
An email bounce occurs when an email is rejected or unable to be delivered to the intended recipient’s inbox. The message “bounces back” to the original sender instead.

What are the main types of email bounces?

The two main types are soft bounces and hard bounces. A soft bounce is a temporary delivery failure that can usually be resolved. A hard bounce is a permanent failure typically due to an invalid email address.

What causes an email to bounce?

Common bounce causes include invalid or mistyped email addresses, inactive accounts, full mailboxes, blocked senders, spam filters, email size limits, and various server issues.

How do you know if an email bounced?

You’ll receive a bounce notification message (also called an NDR or non-delivery receipt) alerting you the email failed. It details the reason, error codes, bounced recipients, and troubleshooting tips.

What should you do when an email bounces?

Review the bounce reason. For hard bounces, remove the invalid email address. For soft bounces, investigate the cause and retry later. Update contact records to avoid sending to that address.

How do you calculate the bounce rate?

Divide your total bounced emails by total emails sent, then multiply by 100 to get a percentage bounce rate. A rate under 2% is considered acceptable.

How can you prevent email bounces?

Strategies include list cleaning, address verification, following email best practices, using high-quality ESPs, dedicated IPs, confirming opt-ins, personalized content, and avoiding spam triggers.

When should you remove a bounced email address from your list?

Promptly delete hard bounced addresses that permanently fail. For soft bounces, you can retry sending once the underlying issue is resolved. Remove soft bounces after extended failed delivery.

How often should you clean your email list?

Clean your list at least quarterly, or more frequently for large volumes. Remove stale addresses not engaging for extended periods.

Can you resend an email that previously bounced?

You can retry soft bounced emails after resolving the temporary factors like overloaded servers. But hard bounced messages should not be resent to the same invalid addresses.