For a vast majority of email marketers, Black Friday and Cyber Monday aren’t just “big”—they’re the biggest. Millions of people are actively looking for deals, and billions of emails are racing to catch their attention.
The busy holiday season isn’t just a big deal for retailers. Research from Stripe and American Express revealed that while core retail spend grew 26% year over year, categories like media & entertainment and travel grew 44% and beauty & health grew 42%.
Plus, charitable giving during the BFCM weekend jumped 80%, with Stripe processing more than $300 million on GivingTuesday alone.
But here’s the hard truth: all that planning, all those promo codes, all those beautifully designed templates mean nothing if your emails don’t make it into the inbox. Landing in spam during Black Friday week is like buying a billboard and covering it with a tarp.
This playbook is your guide to avoiding that fate with prep, math, monitoring and recovery tactics that protect your revenue and your sender reputation.
Here's the TL;DR
The holiday inbox is gridlock. Every bounce, complaint or weak subject line gets magnified under ISP scrutiny.
This playbook walks you through:
- Prepping early (authentication, list hygiene, reputation checks)
- Warming up in October
- Monitoring daily during BFCM and easing down after the surge
With inbox placement math laid out, you’ll see why even a 1–2% lift can mean six figures in revenue—and why deliverability is the lever you can’t afford to ignore.
The Black Friday Deliverability Crunch
Imagine trying to drive across town on the Wednesday before Thanksgiving. The roads are gridlocked. Every tiny fender-bender and distracted driver slows the entire system.
That’s what happens inside inboxes during Black Friday and Cyber Monday (BFCM). In 2024, Twilio SendGrid observed a 15.6% growth in holiday week volume, year-over-year. As a result, inbox service providers (ISPs) like Gmail and Yahoo flip their filters into overdrive. Suddenly, things you got away with in June—a small spike in bounces, a lazy subject line, a questionable list segment—become glaring warning signs.
Your ESP may show you “99% delivered,” but that’s only half the story. Delivered means the server handshake worked. Inbox placement is the metric that tells you whether you got prime inbox real estate or ended up in spam alley.
And that placement gap is where millions of dollars are lost every year.
The Inbox Doesn’t Change. Marketer Behavior Does.
It’s a common misconception that mailbox providers throw up higher walls during Black Friday and Cyber Monday. The truth? The inbox is the same. The filters or requirements haven’t shifted. What changes is sender behavior.
Too many brands treat Cyber Week like a hall pass, cranking up frequency and blasting disengaged lists. That’s what tanks inbox placement, not some hidden ISP conspiracy.
Data from Inbox Monster & Twilio illustrates this point. Inbox placement across industry verticals averaged 91.09% between November 27 and December 3, higher than the often-assumed “ceiling” of 80–85%. In fact, Outlook inbox placement improved from 80% (the previous 90-day average) to 89% during Cyber Week.
Brad Van der Woerd, Head of Customer Success at Inbox Monster, summed it up well: seasonal engagement plus sender best practices contributed to the lift. When marketers respect the rules of engagement, inbox placement improves.
Compared to the prior 90 days, inbox rates ticked up by about 3% during Cyber Week. That’s proof that disciplined sending, aligned with subscriber interest, pays off. The inverse is also true, as peak traffic exposes weak practices and more risk of damaging your deliverability even though the rules are unchanged.
The Revenue Math: Every % of Inbox Placement Counts
Black Friday campaigns are designed to scale. More sends, more clicks, more sales. But the scale goes both ways and every tiny deliverability slip is multiplied.
Picture this: You’re sending 10 million messages. If only 77% of them make it to the inbox, you’ve just locked 2.3 million offers in spam. That’s 2.3 million unopened chances at revenue.
Now let’s run the email math:
- Inbox placement: 77%
- Open rate: 20%
- Conversion: 3%
- Average order value (AOV): $75
Result? About $3.46M in revenue.
Boost inbox placement to 99%, and suddenly you’re pulling in $4.45M. That’s almost a million dollars earned simply by making sure more of your emails land in the inbox, not the spam folder.
Pro Tip: Even a 1-2% lift in inbox placement during BFCM can translate into a six-figure swing in revenue for high-volume senders. That’s why the best time to fix deliverability issues is before you ramp up for the holidays.
💡 Build your own model:
List size × inbox placement % × open rate × conversion × average order value
Before You Hit Send: Fix the Foundation
You don’t notice it when your email deliverability just works. But when it crumbles, your email deliverability becomes the most important need to focus on.
September is the time for a deliverability audit. Don’t treat it as an afterthought—treat it like insurance for a smooth BFCM season.
Here are three things you absolutely must do before the busy holiday season kicks in.
1. Authentication sanity check
It’s easy to forget about your authentication after you set it up… years ago. But it’s a good idea to check-in on it to make sure what you setup is still standing.
- Confirm SPF, DKIM and DMARC are aligned.
- Set up BIMI where supported. That logo in the inbox adds credibility and boosts opens.
- Implement a one-click unsubscribe for your marketing messages. These unsubs must be honored within 2 days.
2. Reputation snapshot
When was the last time you actually looked at your sender reputation? While it might not be the first set of metrics you rush to before or after each send, you should consider getting a snapshot of your sender reputation more often. And definitely right now before the busy holiday season kicks into gear:
- Check your IP/domain reputation with monitoring tools. If you’ve been blocklisted, fix it now.
- Review complaint trends. Even 0.2% complaint rates can get you throttled during peak.
- Scan your list for spam traps and review list acquisition methods. Spam traps are the first sign of poor list hygiene.
3. List hygiene & consent refresh
If your email list is full of non-engagers—and maybe even people who forgot they subscribed—it’ll lead to exponentially poor engagement as you ramp up volume throughout the holiday season. That poor engagement will leave you with a sliding sender reputation.
Consider:
- Suppress non-engagers (12+ months inactive).
- Make sure your unsubscribe process is quick, easy, and painless.
- If you’ve been quiet, run a re-permission campaign before the season.
Warm Up Without Burning Out aka Your October Plan
Marketers often think they can just flip a switch in November. Bad idea. To ISPs, sudden spikes look suspicious. Like a stranger showing up to the party with 500 uninvited friends.
Think of October as your conditioning month.
Ramp schedule by segment
Most senders will be planning to send more email during the holiday season. Potentially shifting from weekly email sends to daily. This shift increases the volume of email you’re sending and ISPs are receiving. Your biggest fans can help make this shift a little easier for ISPs to stomach.
Increase the number of emails you’re sending to your most engaged customers or subscribers and then gradually layer in less actives as your sending pattern builds trust.
Sending from a new domain or subdomain?
The busy holiday season probably isn’t the best time to start sending from a new domain or subdomain. Consider this a pre-pre-holiday season step you should take much earlier in the year.
Read the Monster Guide to IP warming for a full breakdown on how to set yourself up for success sending from a new domain or subdomain.
Your Real-Time Guardrails During BFCM Week
Even with perfect prep, holiday campaigns can veer off course. That’s why you need guardrails in place for the big week.
Seed testing across Gmail, Yahoo and Outlook tells you where you’re landing. Daily checks give you early warnings before performance craters.
If complaints jump, pause. Don’t pour gasoline on the fire by continuing to send, blindly. Instead:
- Segment tighter and focus on your most active and engaged subscribers and customers.
- Tone down urgency in subject lines. It may look misleading to ISPs.
Mailbox providers may throttle you if they sense stress. The smart move is to slow down, not push harder. Keep a holdback list (5–10% of your audience) to resend once your signals stabilize.
After the Surge: Reputation Rehab & Retention
The Monday after Cyber Monday often feels like a deep exhale. But for ISPs, it’s a test: are you consistent, or were you just a seasonal spammer?
- Start by bringing volumes back to baseline. Ease down gently. Going from 2M/day to silence is as suspicious as the initial spike.
- Seasonal shoppers will unsubscribe (fine). Ghosts are more dangerous. Suppress chronic non-engagers to protect your reputation.
- Run a post-mortem. Document what worked, where you hit ISP walls and what thresholds triggered alarms. Your future self will thank you.
The Black Friday Deliverability Playbook Is a Revenue Power Move
Marketers who treat deliverability like a profit lever, not a technical headache, are the ones who win during the busy holiday season. Because even the most dazzling creative can’t convert from the spam folder.
Think of the holiday season as a repeatable cycle:
- Audit in September - October
- Warm up methodically
- Monitor daily in BFCM week
- Adapt when needed
- Reset and record
FAQ: Black Friday Deliverability
How far in advance should I start warming?
Start 6–8 weeks before Black Friday. Late September is best. The earlier, the better.
What’s a healthy complaint rate during BFCM?
Stay under 0.1%. Higher and you risk ISP throttling.
Do transactional emails impact domain reputation?
Yes. If they trigger high complaints, they can hurt your overall domain reputation.
How do I measure inbox placement vs. ESP “delivered”?
Inbox placement testing with seeds/panels shows reality. ESP “delivered” just means your email wasn’t bounced.
Is it smart to re-include unengaged subscribers for the holidays?
No. They’re more likely to harm than help. Run re-engagement earlier or suppress them.
.png)