Holiday Season Deliverability: Key Strategies

The holiday season is one of the highest-volume sending periods of the year, which also makes it one of the highest-risk periods for email deliverability. These strategies help you protect your sender reputation and reach inboxes when it counts most.

The holiday season compresses timelines and amplifies mistakes. Starting your preparation early gives you time to test, iterate, and fix issues before they affect deliverability.

Begin planning at least four to six weeks before your first major send. Test all campaign elements in advance – subject lines, design, links, and call-to-action (CTA) buttons. Rushed, last-minute campaigns are more likely to contain broken links, formatting errors, or missing content.

Use Omnisend's built-in A/B testing to run subject line and content tests before these key dates. Try the AI subject line generator and subject line tester to refine your copy ahead of time.

Mailbox providers like Gmail are highly sensitive to sudden spikes in sending volume. Rapid increases mimic spammer behavior and can trigger deferrals, delivery delays, or spam folder placements.

Gradually increase your sending volume by 25–40% per campaign to give mailbox providers time to adapt. For example:

Maintain this pace rather than jumping straight to your full list size.

Targeting inactive segments of your audience during the holiday season can be tempting, but it carries risks. High bounce rates and low engagement from old email addresses can harm your sender's reputation, leading to placement in spam folders.

Solution: If you must reach out to inactive users, start small: limit this segment to 10% of your total send volume as a test. If engagement is satisfactory, scale up gradually. Always prioritize your active users, as their engagement drives the majority of your revenue.

Increasing the frequency of holiday emails is common, but overdoing it can backfire. If recipients are accustomed to weekly emails and suddenly receive multiple emails daily, you risk causing "inbox fatigue," which can lead to higher unsubscribe and spam complaint rates.

Solution: Balance your sending schedule and tailor content to specific audience segments. Providing value in each email, whether through exclusive deals or personalized recommendations, will ensure your messages are relevant and welcome to recipients.

Switching to a new sender domain right before or during peak season is one of the most common deliverability mistakes. A new domain needs to be "warmed up" gradually, just as a new IP address does. Skipping this process will likely result in emails being placed in the spam folder.

Solution: If a domain change is necessary, start with small volumes (around 100 emails/day) and grow gradually, ensuring good engagement. Ideally, domain changes should not be attempted right before or during the holiday rush.

A significant portion of contacts will open your emails on mobile devices during the holiday season. Emails that are not mobile-optimized create a poor experience and reduce engagement.

Solution: Use responsive designs that adapt to various screen sizes, and test your emails on multiple devices before sending them.

Generic, one-size-fits-all emails are far less effective than personalized ones. Tailoring content to your audience based on their preferences, behaviors, and purchase history can greatly enhance engagement and conversions.

Solution: Segment your email lists and personalize offers to suit each group's interests. Hyper-customization should be a default strategy, especially during the competitive holiday season.

Subject lines can make or break your email campaign. While misleading or clickbait subject lines may drive short-term opens, they can also lead to increased spam complaints and unsubscribes, damaging your sender's reputation in the long run.

Write subject lines that are clear, specific, and accurately reflect the email content. A/B test different versions before major send dates to find what resonates with each segment. Avoid vague urgency phrases ("Last chance!") unless the deadline is real.

Waiting until the last minute to execute your holiday campaigns can lead to rushed, error-prone strategies. Thorough testing is critical to avoid issues like broken links, improper formatting, or missing content.

Solution: Begin planning and testing your campaigns well in advance. Regularly test elements such as subject lines, design, and call-to-action (CTA) buttons to ensure optimal performance.

Finally, don’t let the end of the holiday season derail your efforts. A thorough post-holiday analysis can provide valuable insights to refine your strategy for the following year.

Solution: Conduct a comprehensive review of your email campaign performance to identify areas of success and improvement. This will help build a better strategy for next year's holiday season.