How to prevent emails from going to spam due to high bounce rate before BFCM?
Michael Ko
Co-founder & CEO, Suped
Published 8 Jul 2025
Updated 17 Aug 2025
7 min read
The period leading up to Black Friday Cyber Monday (BFCM) is critical for businesses. It's when email volume often spikes dramatically. However, if your email program has been relatively quiet, with only a few campaigns per month and a noticeable high bounce rate, suddenly ramping up sends can lead to significant deliverability issues, pushing your valuable messages straight into the spam folder. This is a common concern, especially for those new to the intricacies of email deliverability.
A high bounce rate indicates underlying problems with your email list quality or sender reputation. Ignoring these signs and increasing your sending volume during peak times like BFCM will only exacerbate the problem, making it harder for your emails to reach the inbox. Before you launch those crucial holiday campaigns, it's essential to address the root causes of bounces and proactively improve your email deliverability.
Understanding bounce types and their impact
Understanding the types of bounces is the first step in diagnosing deliverability problems. Email bounces typically fall into two categories: hard bounces and soft bounces. Each signals a different issue and requires a specific approach to maintain your sender reputation.
Hard bounces indicate a permanent delivery failure, meaning the email address is invalid, does not exist, or has been permanently blocked. These must be removed from your list immediately, as continuing to send to them severely damages your sender reputation. Soft bounces, on the other hand, are temporary failures, often due to a full inbox, server issues, or the recipient's email server temporarily blocking your message, possibly due to suspicion or volume.
Regardless of the type, a high bounce rate tells mailbox providers that your list is outdated or poorly managed. This can lead to your emails being flagged as spam, even for legitimate subscribers. It's crucial to distinguish between them to implement effective solutions and prevent your emails from ending up in junk folders, especially when trying to minimize bounce impact on deliverability.
Harms sender reputation significantly, leading to spam folder placement or blocklisting.
Remove immediately from your list.
Soft bounce
Temporary failure (e.g., full inbox, server timeout, content suspicious).
Less damaging than hard bounces, but frequent soft bounces can still harm reputation.
Retry sending (ESP usually handles this). If persistent, consider suppressing.
The critical role of email list hygiene
The quality of your email list is arguably the most crucial factor influencing your bounce rate. Old, unengaged, or improperly acquired lists are rife with invalid addresses and spam traps that lead to bounces and blacklisting (or blocklisting). Before any major sending event like BFCM, a thorough list hygiene process is non-negotiable.
Start by identifying and removing all hard bounced addresses. Most email service providers (ESPs) automatically suppress these, but it's good practice to verify. For soft bounces, investigate patterns. Are they consistently from the same domains or related to specific campaigns? Addresses that consistently soft bounce should also be considered for removal. Regularly cleaning your contact data is essential.
Implementing double opt-in for new subscribers is a powerful preventative measure. It ensures that only genuinely interested and valid email addresses are added to your list, significantly reducing future hard bounces and minimizing the risk of hitting spam traps. For existing lists, consider a re-engagement campaign to identify and remove inactive subscribers. These practices are fundamental to reducing bounces through email verification.
Email list hygiene best practices
Validate list: Use an email validation service to proactively identify and remove invalid or risky addresses before sending. This is crucial for maintaining a healthy sender reputation.
Implement double opt-in: Require new subscribers to confirm their subscription. This verifies their email address and confirms their interest.
Segment inactive users: Create a segment for subscribers who haven't engaged in a long time. Consider re-engagement campaigns or removal if they remain unresponsive.
Monitor bounces: Regularly check your bounce reports to understand the causes and take corrective action. Immediately remove hard bounces.
Bolstering your email authentication
Even with a clean list, your emails can still go to spam if your email authentication protocols are not properly configured. SPF, DKIM, and DMARC are fundamental to proving your legitimacy to mailbox providers and preventing spoofing and phishing attempts, which in turn boosts your deliverability.
SPF (Sender Policy Framework) allows you to specify which mail servers are authorized to send email on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a digital signature to your emails, verifying that the content hasn't been tampered with in transit. DMARC (Domain-based Message Authentication, Reporting, and Conformance) builds on SPF and DKIM, giving you the ability to tell receiving servers what to do with emails that fail authentication and provides reports on your email traffic. Properly setting these up is a core step for a simple guide to email authentication.
For BFCM, where email volume often surges, robust authentication is critical. Mailbox providers will scrutinize your sending patterns more closely. If your authentication is weak or absent, they are more likely to filter your emails, assuming they might be malicious or unsolicited. This is particularly important for complying with new sender requirements from major providers like Google and Yahoo.
Beyond technical configurations, the content of your emails and your sending practices play a significant role in avoiding spam folders. Mailbox providers analyze everything from your subject lines to your image-to-text ratio to determine if your email is legitimate or spam-like.
Avoid common spam trigger words and excessive capitalization or exclamation marks. Ensure your HTML is clean and well-structured, and use properly authenticated links within your emails. High bounce rates can also stem from recipient disengagement, where inactive subscribers might mark your emails as spam, signaling to ISPs that your content isn't wanted. Maintaining a consistent sending cadence is also important; sudden, massive increases in volume without proper warm-up can trigger spam filters.
Before the BFCM rush, review your engagement metrics like open and click-through rates. Low engagement combined with high bounces is a red flag. Consider segmenting your list to send to your most engaged subscribers first, gradually expanding to less engaged segments as your deliverability improves. This strategic approach can help improve your average email bounce rate and strengthen your sender reputation, ensuring your BFCM campaigns hit the inbox.
Old sending habits
Infrequent sending: Sending only 2-3 campaigns monthly leads to cold sending IPs and outdated lists.
Ignoring bounce reports: Not analyzing bounce types or reasons, allowing problematic addresses to persist.
Stale email lists: Sending to unengaged or old subscribers increases spam complaints and hard bounces.
BFCM preparation
Gradual ramp-up: Slowly increase email volume over time to warm up your sending reputation.
Pre-BFCM list scrub: Prioritize cleaning invalid addresses and re-engaging inactive subscribers.
Segmented sending: Target your most engaged audience first, then expand to broader segments.
Conclusion
Preventing emails from going to spam due to high bounce rates before BFCM requires a multi-faceted approach. By thoroughly cleaning your email lists, strengthening your authentication, and adopting best practices for content and sending volume, you can significantly improve your deliverability. This proactive preparation is crucial to ensure your important holiday messages reach the inbox and drive conversions, rather than being caught in spam filters or bouncing.
Remember, a low bounce rate (ideally below 3%) is a strong indicator of a healthy email program and a positive sender reputation. Investing time now to address existing bounce issues will pay dividends during the critical BFCM period and beyond, securing your place in the inbox.
Views from the trenches
Best practices
Always retrieve and analyze the raw bounce messages from your ESP to understand specific reasons.
Prioritize cleaning invalid email addresses before increasing sending volume.
Implement a double opt-in process for all new subscribers to maintain list quality.
Common pitfalls
Ignoring 'unclassified' bounces instead of digging into the raw bounce messages.
Ramping up email volume without first addressing existing high bounce rates.
Sending to an old, unengaged list without prior re-engagement or cleaning efforts.
Expert tips
Deliverability issues and high bounce rates are often symptoms of the same underlying problems with list quality or sender reputation.
A sudden shift in open rates by recipient domain can indicate mail starting to go to bulk folders.
Verify your email audience selection and check for any spam blockages before major campaigns.
Expert view
Expert from Email Geeks says to examine the specific bounce messages to understand why emails are bouncing, rather than relying solely on classification labels.
2023-11-02 - Email Geeks
Expert view
Expert from Email Geeks says that a high bounce rate often shares underlying causes with emails going to spam, such as poor list quality.
