The holiday season brings a flood of promotional emails, and just as many spam filters tighten their defenses.
If you want your campaigns to reach real inboxes (and real buyers), you need more than clever subject lines or flashy graphics. You need strong deliverability practices that help your messages bypass spam folders and stay visible where it matters most.
Below, you’ll find the most important do’s & don’ts to keep your email deliverability strong all season long.
Do: Warm Up Your Sending Domain Before Holiday Campaigns
As the holidays approach, your sending volume often spikes, especially if you’ve been quiet for a while. Sudden surges in activity can trigger spam filters.
Gradually increase your sending frequency in the lead-up to the big push. Start with smaller segments of engaged subscribers and expand over time. This gradual warm-up informs mailbox providers, such as Gmail & Outlook, that your domain is trustworthy and consistent.
Pro Tip: Use a mail tester for businesses before sending. The test will show whether your domain reputation or IP has issues that could cause deliverability drops during your busiest season.
Don’t: Use Misleading Subject Lines or “Trick” Tactics
It’s tempting to grab attention with subject lines like “Re: Your Order” or “Your Package Is Ready.” But those misleading tactics invariably backfire. Spam filters detect them, and subscribers lose trust fast.
Be creative but honest. Promise value that matches your content. Subject lines like “Your Exclusive Holiday Offer Ends Tonight” work when the content truly delivers on that promise.
Your subscribers (and their inbox filters) reward authenticity.
Do: Monitor Engagement & Prune Unresponsive Subscribers
Holiday campaigns often attract new signups & re-engagement opportunities, but not everyone stays active. Regularly monitor open rates, clicks, and bounces. Remove or suppress contacts who haven’t engaged after multiple attempts.
Mailbox providers reward consistent engagement. If most recipients open, read, or click your messages, you signal to algorithms that your emails belong in the inbox.
Think of pruning as maintenance: it strengthens your list’s health and helps future campaigns perform even better.
Don’t: Send Massive Blasts to Cold or Inactive Lists
Sending emails to subscribers who haven’t engaged in months (or years) is one of the quickest ways to damage your sender reputation. High bounce rates, spam complaints, and low opens tell ISPs your emails don’t belong in the inbox.
Instead, segment your list. Focus on active users first, then re-engage the rest gradually with a separate campaign. If they still don’t respond, it’s better to remove them than to risk your overall deliverability.
Your list size doesn’t matter if your reputation tanks. Engagement does.
Do: Authenticate Your Emails with SPF, DKIM & DMARC
Email authentication is the foundation of deliverability. Without proper setup, mailbox providers can’t verify your identity, and your messages may be marked as suspicious or spoofed.
Make sure your domain includes:
- Sender Policy Framework (SPF): Lists authorized mail servers allowed to send on your behalf.
- DomainKeys Identified Mail (DKIM): Adds a digital signature verifying message integrity.
- Domain-based Message Authentication, Reporting & Conformance (DMARC): Tells providers what to do if SPF or DKIM checks fail.
Pro Tip: Don’t forget about BIMI. If you’re unsure whether any of these four are set up correctly, run your email through an authentication & BIMI checker. You’ll get an instant technical breakdown and clear next steps to fix any gaps.
Don’t: Ignore Domain Reputation & Blacklist Status
Even if your content looks perfect, a poor domain reputation can sabotage your deliverability. Being on a spam blacklist or having a low-trust sender score can quietly kill your inbox placement without warning.
Check your sender reputation regularly, especially during the holidays when ISPs are on high alert for spammy behavior. If your domain lands on a blacklist, act fast: review your sending practices, correct the issue, and submit removal requests.
Using a quick blacklist look-up tool can flag blacklist issues before your holiday campaigns go live.
Do: Personalize & Segment Your Holiday Messaging
Personalization isn’t just about using first names; it’s about sending the right message to the right audience. A customer who bought from you last month needs a different offer than someone who hasn’t opened your emails all year.
Segmentation improves engagement metrics like opens & clicks, which in turn boosts your sender reputation. For example:
- Send loyalty discounts to repeat customers.
- Offer gift guides to new subscribers.
- Highlight shipping deadlines to local buyers.
These data-driven adjustments make your campaigns feel relevant and keep spam filters from treating them as bulk promotions.
Don’t: Overload Emails with Images or Links
While visuals are important for holiday promotions, image-heavy emails with little text often look like spam. Filters analyze image-to-text ratios, and too many links (especially tracking URLs or redirect chains) can raise red flags.
Keep a healthy balance between copy & design. Use clear text descriptions alongside your graphics, and limit links to essential CTAs. A single, well-designed button performs better and delivers more reliably than a cluttered wall of links.
Do: Test Every Campaign Before You Send
Even the most experienced marketers miss small details. A missing authentication record, an unoptimized image, or a broken link can derail your deliverability. That’s why pre-send testing is essential.
Run every campaign through a primary inbox placement tool before hitting send. You’ll instantly see whether your message passes key deliverability checks, so you can fix issues before they hurt your inbox placement.
This single step can save an entire season’s worth of email performance.
Don’t: Wait Until It’s Too Late to Diagnose Problems
If you wait until open rates drop, you’ve already lost momentum. Inbox placement issues take time to recover. Once ISPs label you as a risky sender, it can take weeks of consistent behavior to rebuild your reputation.
The best defense is prevention. Test early, monitor often, and track your deliverability weekly throughout the holiday rush.
Do: Take Action to Improve Your Campaigns Today
As you prepare your holiday campaigns, they depend on more than catchy promotions or festive designs. They depend on inbox placement. Think of it like gift wrapping. The content of your email is the gift itself, but deliverability is the wrapping that gets it noticed. Without the right wrapping, the gift may be ignored, misplaced, or tossed aside.
The difference between success and spam often comes down to the fundamentals:
- Do: Warm up your domain, authenticate properly, and send to engaged subscribers.
- Don’t: Blast cold lists, overload with images, or neglect your sender reputation.
By following the above do’s and steering clear of the don’ts, you put your campaigns in the best position to succeed. Each improvement in inbox placement translates directly into more opens, clicks, and conversions. With the right tools & strategies in place, you’ll ensure your holiday emails get read, so your offers can turn into revenue.