What causes high bounce rates on Cyber Monday and how to prevent them?
Michael Ko
Co-founder & CEO, Suped
Published 18 May 2025
Updated 15 Aug 2025
8 min read
Cyber Monday stands as one of the most critical days for online retailers. The surge in traffic and transactions can be incredibly rewarding, but it also brings unique challenges. During this peak period, even minor issues can be magnified, leading to significant problems like exceptionally high bounce rates that can undermine your carefully planned campaigns and erode potential revenue.
A high bounce rate on Cyber Monday can stem from a variety of sources, ranging from strained website infrastructure to overzealous email sending practices and outdated contact lists. When systems are pushed to their limits, email providers and website servers become more sensitive, often resulting in increased filtering or rejections that wouldn't typically occur during quieter periods.
Understanding the specific causes behind these spikes is the first step toward prevention. We will explore the common reasons for elevated bounce rates during this high-stakes shopping event and outline actionable strategies to safeguard your email deliverability and website performance, ensuring your messages reach inboxes and your site remains accessible to eager shoppers.
The unique pressures of Cyber Monday
The sheer volume of email campaigns and website traffic on Cyber Monday creates an environment unlike any other day of the year. This intense activity puts immense pressure on internet service providers (ISPs), email servers, and website hosting infrastructure. What might be a non-issue during a typical week can become a major bottleneck or trigger for filtering systems under the holiday strain. This often means that ISPs become more conservative in their filtering, meaning borderline senders might suddenly find themselves facing increased rejections.
We often see spikes in bounce rates specifically from smaller domains or those managed by larger parent companies like AT&T, which encompasses domains such as sbcglobal.net, bellsouth.net, and att.net. These providers, along with others like optonline.net and charter.net, may have stricter receiving policies or become overwhelmed more easily than major players like Gmail or Yahoo. The increased volume can push even normally compliant senders into a grey area, leading to temporary blocks or soft bounces as systems struggle to cope.
The fundamental issue is capacity and reputation. When millions of emails are being sent and received, and websites are experiencing record traffic, any perceived misstep, no matter how minor, can result in a disproportionate number of bounces. This highlights the importance of robust preparation and diligent monitoring to ensure your campaigns reach their intended audience.
Identifying the culprits behind email bounce spikes
When bounce rates spike on Cyber Monday, especially from smaller domains, it often points to issues related to email list quality or sudden changes in sending behavior. Even a list that performs adequately during off-peak times can become a liability when email volume dramatically increases. ISPs become more aggressive in their filtering, looking for any sign of a less-than-stellar sender reputation.
Most bounces during high-volume periods tend to be soft bounces, which are temporary delivery failures. These can occur if the recipient's mailbox is full, the server is temporarily unavailable, or, critically, if the receiving server is experiencing high traffic and temporarily rejecting mail to protect its resources. This scenario is particularly common on Cyber Monday. While temporary, a high volume of soft bounces can still negatively impact your sender reputation, pushing subsequent emails to spam folders or leading to future hard bounces.
It's crucial to understand your audience and their engagement levels. Sending to inactive or unengaged contacts can lead to higher bounce rates, as these addresses may be abandoned, invalid, or converted into spam traps. During holiday rushes, the temptation to maximize your list by including less engaged segments can backfire severely.
Understanding email bounce types
Hard bounce: A permanent delivery failure, often due to an invalid or non-existent email address. These should be removed from your list immediately to protect your email deliverability.
Soft bounce: A temporary delivery failure. This could be due to a full inbox, server issues, or the recipient's server throttling your emails due to volume or reputation concerns, which is common during Cyber Monday. For more on this, read about what causes a sudden spike in email bounce rates.
Common email bounce causes
List quality: Sending to old, unengaged, or unverified contacts.
Sender reputation: A compromised reputation or too many spam complaints.
Slow page load speed: Visitors abandon sites that take too long to load. Studies show that a 3-second delay can lead to a 40% bounce rate. For more information, see this article on website bounce rate reasons.
Poor mobile experience: Non-responsive design on mobile devices.
Irrelevant content: Landing page content doesn't match user expectations from the ad or email.
Technical glitches: Broken links, errors, or confusing navigation.
Bot traffic: Malicious bots can inflate bounce rates without actual human engagement. Read more about what bot traffic is.
Mitigating website bounce rates on Cyber Monday
Optimizing your website for Cyber Monday traffic is paramount to avoiding high bounce rates. The absolute top priority is page load speed. With increased server load and user impatience, every millisecond counts. Implement caching, optimize images, and use a content delivery network (CDN) to ensure your pages load almost instantly, even under heavy traffic.
Beyond speed, a seamless user experience across all devices is critical. Ensure your website is fully mobile-responsive and easy to navigate. A confusing layout, broken links, or excessive pop-ups can quickly frustrate visitors and send them bouncing to a competitor. Simplify the checkout process and ensure calls to action are clear and prominent.
Finally, ensure your landing page content is highly relevant to the promotional messages that drove traffic to your site. Misleading titles or descriptions can lead users to immediately leave if the page doesn't meet their expectations. Conduct A/B tests on your landing pages beforehand to identify the most effective layouts and copy.
Proactive strategies for email deliverability
To preempt high email bounce rates on Cyber Monday, list hygiene is non-negotiable. Before the holiday rush, thoroughly clean your email list by removing inactive or invalid addresses. Regularly segmenting your audience and sending to highly engaged contacts first can significantly improve your deliverability and prevent emails from going to spam. This practice helps maintain a strong sender reputation, which is critical during peak sending times.
Sender reputation is your most valuable asset. ISPs (Internet Service Providers) like AT&T use it to determine if your emails are trustworthy. If you see high bounce rates specifically from AT&T-related domains, it might indicate an issue with your reputation or a temporary throttling from their side due to high volume. Monitor your domain reputation through tools and pay close attention to any warnings or blacklisting (or blocklisting) events, even if temporary. Using a robust blocklist monitoring service can help you quickly identify and address these issues.
Furthermore, ensure your email authentication protocols—SPF, DKIM, and DMARC—are correctly configured and enforced. These protocols prove to receiving servers that your emails are legitimate and not spoofed. A high volume of unauthenticated mail, especially during peak periods, is a major red flag that can lead to increased bounces and emails going directly to the spam folder. Platforms like Klaviyo, as mentioned by one marketer, often provide guidance on these setups. Reviewing your email platform's bounce logs for specific codes can provide deeper insights into the root cause, allowing you to fine-tune your sending strategy. For more tips on reducing email bounce rates, consider this article from Klaviyo.
Essential Cyber Monday email checklist
Clean your lists: Remove unengaged subscribers and invalid addresses.
Segment your audience: Prioritize highly engaged segments for critical campaigns.
Monitor blocklists: Regularly check if your IP or domain is listed on any major email blocklist.
Views from the trenches
Best practices
Actively analyze your email list for the oldest and least active segments, especially before major sending events. Understanding these 'bad pots of data' can help you segment more effectively.
Segment your email list into 2-3 groups based on engagement and likelihood to generate revenue. Send to the most engaged segments first, then the next best, and so on. This approach can help isolate potential issues.
Always prioritize email list hygiene. Regularly removing invalid or inactive email addresses prevents unnecessary bounces and maintains a healthy sender reputation, crucial for peak sending times.
Common pitfalls
Increasing email sending volume dramatically during holidays without sufficient preparation can push your domain into a 'borderline' deliverability state, leading to higher soft bounces.
Assuming an email list is good solely based on past opens, clicks, or conversions without analyzing its least active or oldest segments can lead to unexpected deliverability issues during high-pressure periods.
Ignoring specific bounce codes or responses from email service providers, especially during peak seasons, means missing crucial insights into why deliverability is suffering.
Expert tips
Investigate common provider, filter, or blocklist issues if you see widespread bounce spikes across smaller domains. Checking MX records for affected domains can sometimes reveal a shared email provider causing the problem.
If bounce rates immediately return to normal after a holiday surge, it strongly suggests temporary throttling or stricter filtering by ISPs due to the increased load. Continue to analyze your data proactively.
Educate stakeholders on the importance of list quality over quantity, especially during the holidays. Showing concrete examples of disengaged recipients can help illustrate the negative impact of 'maximizing' the list.
Marketer view
Marketer from Email Geeks says they experienced more than 15x higher bounce rates on Cyber Monday from small domains, like sbcglobal.net and att.net, compared to previous weeks, even with a similar list. They suspected a common provider, filter, or blocklist might be the cause, but their platform didn't provide detailed bounce reasons.
2020-12-03 - Email Geeks
Marketer view
Marketer from Email Geeks says that the first three domains mentioned by another marketer (sbcglobal.net, bellsouth.net, att.net) are all AT&T properties. They suggested checking the basics for AT&T email support and analyzing the list, especially the least active and oldest segments, as increased volume during Black Friday period can make receiving servers more likely to make arbitrary decisions.
2020-12-03 - Email Geeks
Sustaining success beyond Cyber Monday
Cyber Monday's high bounce rates are often a symptom of underlying issues that are simply exacerbated by extreme traffic and sending volumes. While the immediate goal is to prevent and mitigate these problems during the sales event, the lessons learned are crucial for long-term email deliverability and website health.
By proactively managing your email lists, ensuring robust website performance, and diligently monitoring your sender reputation and blocklist (blacklist) status, you can minimize the risk of high bounce rates. These strategies not only ensure successful Cyber Monday campaigns but also contribute to healthier, more resilient digital operations year-round.
We often see spikes in bounce rates specifically from smaller domains or those managed by larger parent companies like AT&T, which encompasses domains such as sbcglobal.net, bellsouth.net, and att.net. These providers, along with others like optonline.net and charter.net, may have stricter receiving policies or become overwhelmed more easily than major players like 
Gmail or 
Yahoo. The increased volume can push even normally compliant senders into a grey area, leading to temporary blocks or soft bounces as systems struggle to cope.
Klaviyo, as mentioned by one marketer, often provide guidance on these setups. Reviewing your email platform's bounce logs for specific codes can provide deeper insights into the root cause, allowing you to fine-tune your sending strategy. For more tips on reducing email bounce rates, consider this article from Klaviyo.
