Klaviyo BFCM strategy (2025): Protecting deliverability & limiting list fatigue

BFCM (Black Friday Cyber Monday) is the single most competitive inbox moment of the year, with brands flooding customers with promotional content. In 2025, mailbox providers like Gmail and Yahoo are enforcing stricter authentication (DMARC, SPF, DKIM) and paying closer attention to sender engagement signals, making traditional list blasting obsolete and risky. 

The BFCM landscape has shifted dramatically. Key stats from 2024 illustrate the changes:

• Over 5 billion emails were sent during BFCM weekend 2024, a 26% YoY increase from the previous year.
  
• Despite higher email volume, open rates fell to 13-15%.
  
• 41%+ of consumers are creating “burner inboxes” for marketing emails and discounts, avoiding their primary accounts.

The stakes are high: unprecedented subscriber volume, inbox wars across increasingly strict mailbox providers, and peak revenue events compressed into a few critical days. 

Klaviyo stands out as a powerhouse for BFCM email marketing, and luckily, our team is packed with 15+ Klaviyo specialists who have successfully supported over 1,000 clients.

Looking to supercharge your Klaviyo BFCM strategy? Struggling with Klaviyo list fatigue? 

We’ve got you covered. 

Below is a no-nonsense guide built on current best practices, Klaviyo’s capabilities, and insights from Klaviyo specialists operating at the bleeding edge of email marketing. 

This is your complete BFCM Klaviyo deliverability strategy for this year. Let’s roll!

Klaviyo email warmup before BFCM

Success on BFCM  hinges on your emails actually reaching the inbox, especially since you’ll be sending aggressively (multiple emails daily, to the entire list). Therefore:

• Maintain a strong sender reputation: Ensure Gmail, Outlook, and other providers see your emails as trustworthy; poor reputation sends messages to spam.
  
• Target engaged contacts only: Focus campaigns on your most active audience instead of blasting your entire list.
  
• Aim for high open rates: Target at least 50% with engaged segments, because strong engagement signals value to inbox providers, boosting deliverability.
  
• Send consistently: Email at least three times per week to build a solid sending history; sudden bursts during Black Friday after inactivity risk spam flags.
  
• Prioritize value over promotions: Shift to non-promotional emails that entertain, inform, and build anticipation. This also helps prevent list fatigue in Klaviyo.
  
• Leverage storytelling and education: Use emails for founder stories, behind-the-scenes content, product education (how-to’s, benefits, myth-busting), social proof (testimonials, UGC), and concise content suited for multitasking readers.

Source: Email Love

How to fix Klaviyo email deliverability

Fixing poor email deliverability is crucial because it costs thousands in lost revenue when emails land in the spam folder. Below, we outline three steps to avoid a Klaviyo deliverability drop.

1. Get your technical setup right

The first thing in any BFCM Klaviyo deliverability strategy is getting the technicals fixed. Setting up the correct technical standards improves trust with inbox providers:

• Check for a Branded Sending Domain: Make sure that you are using a branded sending domain instead of the default Klaviyo domain. This improves deliverability.
  
• Set Up Default Sender Email: The sender address should be from your new branded sending domain.
  
• Set Up a DMARC Record: DMARC leverages SPF and DKIM to verify email authenticity and safeguard your domain from unauthorized use. It is configured as a new TXT record in your DNS settings.
  
• Set Up a BIMI Record: This allows a brand logo to appear next to your email address in the inbox, building brand awareness and trust. It is expensive.
  
• Use Staggered Send Times: Instead of blasting a campaign all at once, use the “gradual send over several hours” option to spread out your send across multiple batches.

Getting your technical setup right lays the groundwork for inbox trust, ensures your emails reach real subscribers, and strengthens your brand presence every time you hit “send.”

2. Clean up to maintain Klaviyo list health 

To improve your email deliverability, you must prioritize the quality of your list over the size. The core strategy is to suppress unengaged profiles:

• Unengaged (180 Days): Before BFCM, suppress contacts with no opens or site activity in the last 180 days who’ve received at least 15 emails. (Alternatively, instead of full suppression, test a 10% sample in a regular campaign to attempt re-engagement while minimizing deliverability risk.)
  
• Didn’t Receive Email (1 Year): Suppress profiles created over a year ago with 0 sends and no website activity. Sending to these cold contacts right before BFCM risks spam flags and weakens overall deliverability.
  
• Never Opened Email: Suppress all profiles over 365 days old that have never opened an email. They won’t recognize your brand during BFCM, so avoid wasting resources.
  
• Marked as Spam: Immediately suppress anyone who has marked your emails as spam. Spam complaints are fatal to Klaviyo email deliverability during BFCM.
  
• Bounced Emails: Suppress if the email has experienced a hard bounce at least once, and a soft bounce at least 4 times.

Source: Klaviyo

The strategy is straightforward: build precise segments, export them, and suppress inactive profiles. Since Klaviyo uses profile-based pricing, monthly list cleaning is ideal. 

For smaller lists where cleaning won’t impact your plan tier, a quarterly cleanup is still effective for offsetting Klaviyo list fatigue. 

3. Improve & maintain sender reputation in Klaviyo

Break the low-engagement cycle by emailing your most active contacts first—this “primes” inbox providers to boost and maintain sender reputation in Klaviyo:

• Create Engaged Segments: Segment contacts who have opened/clicked emails, been active on-site, or placed orders in the last 14, 30, 60, and 90 days.

Foundation Phase (Weeks 1 & 2)

• Turn off all flows except Welcome Series, Post-Purchase, and Abandonment flow.
  
• Send 3 campaigns/week to the 14-day Engaged Segment (6 emails total).

Validation Phase 1 (Weeks 3 & 4)

• Check open rates:
  
  • If <50%, continue with the 14-day segment for 2 more weeks.
    
  • If ≥50%, send 3 campaigns/week to the 30-day Engaged Segment. 

Validation Phase 2 (Weeks 5 & 6)

• Check open rates:
  
  • If <50%, continue with the 30-day segment for 2 more weeks.
    
  • If ≥50%, send 3 campaigns/week to the 60-day Engaged Segment. 

Expansion Phase

• If open rates remain ≥50%, expand to the 90-day Engaged Segment.
  
• Turn all flows back on as email reputation improves.
  
• Continue expanding to 120, 150, and 180-day segments as long as open rates stay ≥50%.

Starting with your most engaged contacts and then gradually expanding outward systematically strengthens your sender reputation, maximizes inbox placement, and drives meaningful engagement. This “phased approach” also serves as a safe sending strategy in Klaviyo that balances growth with long-term deliverability.

4. General deliverability tips

The secret to good email deliverability is to ensure your audience gives positive engagement (opening, clicking, responding). Save these tips to prevent list fatigue in Klaviyo:

• Content Focus: Create engaging content (storytelling, tips, entertainment) that people like to open, and avoid overloading with sales.
  
• Plain Text Emails: Use 1 or 2 plain text emails monthly for high open and click rates.
  
• Text-based emails: These emails are simple, personal, and stand out amidst heavily designed campaigns. They drive strong conversions while easing the workload on your design team, making it easy to send 2–3 times per day.
  
• Call to Actions (CTAs): Use prominent buttons above the fold, include product categories in the footer, limit products to 3–5 per email with individual “Shop Now” buttons, and end blocks with a “Shop All” button.
  
• Length & Tone: Make your emails short and easy to digest (less than a minute to read), using infographics, charts, and graphs.
  
• Sales Events: Maximize sales events to once a month or every other month to avoid annoying subscribers.
  
• Invisible Text in Footers: For emails that are mostly image-heavy, which can trigger deliverability issues, include a block of about 200 words from your “About Us” page in the footer. Set the text color to match the background so it remains invisible to readers but detectable by inbox providers, improving your email’s deliverability.

These techniques will help reduce subscriber fatigue in Klaviyo by mixing valuable, story-driven content with sales messaging at a sustainable cadence.

Klaviyo deliverability protection: The non-negotiables

BFCM deliverability isn’t won during the sales weekend—it’s earned in the weeks leading up to it. Inbox providers are smarter, stricter, and far less forgiving of lazy sending practices. Accordingly, keep these “non-negotiables” in mind while optimizing Klaviyo email deliverability:

• Start preparing for BFCM weeks in advance—complete warm-ups, authentication, and testing by early November to avoid last-minute deliverability issues.
  
• Implement SPF, DKIM, and DMARC with alignment. Keep spam complaints under 0.1%, use valid PTR records, one-click unsubscribes, and active reply-to addresses.
  
• Remove inactive or unengaged contacts before the holidays to prevent hitting spam traps and send tailored content based on past engagement and interests.
  
• Warm dedicated IPs over at least 30 days with consistent volume; sender reputation builds through steady engagement, not one-time blasts.
  
• Avoid deceptive email subject lines or fake transactional formats; align “from,” “reply-to,” and sending domains to maintain credibility and prevent phishing flags.
  
• Don’t rely on “transactional” labels to bypass filters. Providers prioritize engagement. Keep promotional and transactional streams separate to protect key messages.
  
• Test your emails across devices, confirm links and images work, and remember to prepare backup campaigns for underperformers while monitoring key metrics daily.
  
• Remember that no ESP can override poor sending habits; strong deliverability comes from good practices and genuine engagement.
  
• Use third-party tools for deliverability testing, like GlockApps, Mail-Tester, MXToolbox, and Inbox Monster. 

Inbox trust is earned, not granted. Brands that plan early, clean their lists, and play by the rules will dominate the inbox long before the first “Black Friday Deal” goes live.

Own the inbox this BFCM—with Mavlers!

As BFCM approaches, inbox competition will hit record highs—and only brands that prepare early will stay visible. The line between inbox success and the spam folder comes down to three things: technical precision, clean data, and consistent engagement. By tightening your authentication setup, pruning inactive profiles, and keeping your best subscribers active, you’ll safeguard deliverability and turn every email into a real revenue driver.

Avoid spam folders and wasted sends this BFCM. Let our Klaviyo email marketing experts guide you—book a 30-minute, no-obligation call to discuss Klaviyo BFCM strategy.