As the festive season rolls in and your send queue fills with special offers and jolly jingles, there’s a sneaky deliverability truth: the words “Merry Christmas” won’t get your mail blocked. What will? Messy data, spam traps, unexpected volume spikes and missing authentication.

So if you want your emails in the nice list rather than the dreaded spam folder, read on. And yes, we’ll mention mince pies (because you’d ask if we didn’t).

Festive words won’t hurt, your data will

It’s tempting to think that all you need is a cheerful subject line and you’re sorted. But according to Spotler’s guide to improving email deliverability, the real threats to inbox placement are poor list hygiene, spam traps, high bounce rates and unengaged cold segments.

The Data & Marketing Association (DMA) echoes this, noting that sender reputation and data quality are the biggest determinants of inbox success. Festive keywords rarely impact filtering, but inconsistent sending, bad authentication and neglected data can.

In other words, you can say “Ho ho ho” all you like, but if your database hasn’t had a spring clean since last Boxing Day, you’ll be on the naughty list faster than you can say “seasonal segment”.

Keep data hygiene high and avoid recycled traps

Cleaning your database isn’t glamorous, but it’s essential. A high bounce rate and repeated hits on spam traps will block your route to the inbox. As explained in Spotler’s deliverability resources, you should remove hard bounces, inactive users and any addresses that could trigger spam systems.

The DMA’s Email Deliverability Whitepaper reinforces this point, showing that list hygiene, not content, drives most placement issues. According to their research, data decay of 22% per year is typical in the UK, meaning nearly a quarter of addresses can go bad in just twelve months.

Think of it like clearing the chimney before Santa arrives. Skip it, and you’re getting soot, not presents.

Helpful checklist:

  • Remove hard bounces and unknown users
  • Segment out cold or unengaged contacts and treat them differently
  • Avoid purchasing lists or recycling old data without re-consent
  • Monitor complaint rates, trap hits and engagement decay
  • Review inactive contacts every quarter, just as the DMA benchmarks recommend

Warm up segments and throttle cold audiences

High volume spikes or mailing cold data at the last minute is like arriving at a party dressed as Santa at 11.59 pm, it raises eyebrows. Smooth, consistent sending builds reputation over time. Spotler recommends maintaining regular sending patterns and gradually increasing volume when using a new IP or domain.

The DMA also highlights volume consistency as a core component of sender reputation, encouraging brands to “treat ISPs as long-term relationships, not short-term flings.” (We couldn’t have put it better ourselves.)

For cold segments, send a soft re-engagement or warming series first rather than blasting full offers. Treat them like guests you haven’t seen in a year, welcome back politely, don’t push presents immediately.

Authenticate properly and monitor inbox placement trends

Email authentication (SPF, DKIM, DMARC) isn’t optional, it’s your brand ID check at the door. Spotler’s deliverability blog explains how unauthenticated domains damage deliverability and how filters rely on reputation and authentication to judge your mail.

The DMA’s Deliverability Report backs this up, showing that 97% of marketers with proper authentication see higher inbox rates. They also note that open rates alone are unreliable as performance metrics, engagement depth matters more. (WARC coverage here)

Once everything is set up, keep monitoring:

  • Deliverability versus inbox placement (delivery is sent, placement is in inbox)
  • Engagement metrics (opens, clicks, unsubscribes)
  • Volume anomalies and bounce spikes
  • Feedback loops and spam complaint data

If you’re using Spotler SendPro, you can easily track domain performance and spot issues before they snowball.

Why it matters (and yes, you can still mention mince pies)

If your email lands in the spam folder, not only does your festive offer vanish, but your sender reputation takes a hit for weeks. The DMA’s Email Benchmarking Report shows that average inbox placement rates for UK brands sit around 96–98%, but that drops sharply when poor data and inconsistent sending creep in.

And yes, it’s fine to include festive imagery, seasonal subject lines or mince pie references (we’d be worried if you didn’t), but the key is that those creative touches don’t mask sloppy sending practices.

According to Spotler’s Email Deliverability Guide, creative tone only works if technical hygiene is in place. In other words, your best pun about “sleighing it this Christmas” won’t matter if your domain reputation’s in the bin.

The takeaway: be on the nice list for deliverability

To make sure your festive campaigns land in the inbox, not the junk folder, focus on:

  • Clean, engaged data with no hidden spam traps
  • Gradual warming of audiences and consistent sending volume
  • Proper authentication and vigilant monitoring of placement trends
  • And yes, by all means include those mince pie jokes, just don’t rely on them to save a bad list


Want to make sure your Christmas emails get delivered, opened and clicked?
Learn more with our deliverability blog with checks, tools and tips.