Email deliverability do’s and don’ts for the holiday season

As the days get shorter and Halloween decorations start appearing on the shelves of your local stores, you know the countdown to the holiday season has begun. While it’s great to enjoy the seasonal change with a warm pumpkin spiced beverage, it’s important to ask yourself “is my email marketing program correctly set up to take full advantage of this peak buying period?” Are you aligned with what your customers want, ready to send engaged emails with relevant content, and maximize your profits by successfully landing in the inbox? 

We're here to help you with all of the above. We'll review some important Do’s and Don’ts that will help your emails navigate the busy electronic highway to arrive successfully in the inbox, and not get lost in the junk folder. Before we do so, it’s useful to understand what happens in the email world during the busy period leading to Christmas. 

The big picture of "email"

Global email volume has been increasing year on year with approximately 281 billion emails sent and received daily in 2018, and this volume is expected to increase to over 347 billion daily emails by 2022.

It’s not surprising that email volume dramatically increases leading up to the holidays, as more brands are sending more emails during this time to capitalize on Black Friday/Cyber Monday sales and Christmas shopping. In 2017 ReturnPath reported a global email volume for their consumers to be as high as 78% above average on Thanksgiving Day. At Emma we saw that, on average, our customers sent 17% more email in November 2018 than for the whole of 2018, and we expect similar email volumes in 2019.

Engagement, sender reputation, and email fatigue

With emails being sent in both high volume and high frequency, it’s easy for recipients on your list to suffer from email or inbox fatigue. Email fatigue is when the sheer volume of emails being received is exhausting, and people will begin ignoring emails, deleting them unopened, unsubscribing, or even worse, marking them as spam. All of these actions impact your sender reputation and could result in your emails being filtered to the spam folder rather than the inbox. We’ve written more on engagement and sender reputation under “consider what ISPs say about engagement” in our article “Why is my email going to the spam folder?” 

The increase in email traffic also impacts the servers of inbox providers and internet service providers (like Gmail, Verizon, Microsoft), which can lead to longer email delivery times and more emails being filtered as spam or being blocked outright.

Now that we have an understanding of what’s happening in the email world during the holidays, let’s looks at some Do’s and Don'ts to keep you on the “nice sender” list and off the “naughty” one.


1. Send emails to people who have directly and specifically opted in to receive your email content. Sending emails that people didn’t sign up for is considered SPAM. Not only is this against Emma’s anti-spam policy, sending irrelevant and unwanted content will result in poor engagement, including low-open rates and high-spam complaints. This directly damages your sender reputation and will impact the performance of your future emails.

2. Make sure you have DKIM email authentication set up in your account. DKIM authentication authorizes Emma to send emails on your behalf and shows the recipient server (the server receiving the email) that your emails are trustworthy. If your emails are seen as trustworthy, they are less likely to be rejected or put in the spam folder.

3. Review the performance of your emails over the last 6-12 months and segment out inactive contacts. If someone hasn’t opened a single email you’ve sent them in the last 12 months, it’s unlikely they will open the next ones especially given this busy period. A consistent low open rate shows inbox providers that people don’t want your emails, and to protect the inbox of their users providers will start blocking or filtering your emails.

4. Pay attention to email fatigue and the user experience from your subscriber’s point of view. If you see a particular email didn’t perform well, it can be tempting to simply resend the same email right away to the non-openers. You may get a few more opens and clicks but an overall low open rate will still affect your sender reputation. If you do need to resend an email, wait at least 24 hours. Changing the subject line and email content can make your audience take notice. You can also do some A/B tests to determine which subject line and content work best for your subscribers. 

5. Set up a preference center so that you can collect important information directly from your subscribers. The days of “spray and pray” are long gone, and the key to a successful email marketing strategy is to send both relevant and targeted content. You can use the information your subscribers provide you to segment your list and send personalized emails that increase open rates and traffic to your website landing page. 

6. Send automated triggered emails like welcome emails, which will build a strong relationship with new subscribers and manage their expectations. Welcome emails generally have great engagement, like high open rates and link clicks. This high engagement boosts your sender reputation, which improves your sender reputation and improves your deliverability. 

7. Use triggered emails to send a reactivation email to the least active subscribers to gauge whether they want to remain on your list. For example, you could create a segment of subscribers who haven't opened any emails in the last 180 days and send them a reactivation email. If this segment captures a large percentage of your list, you may want to stagger the reactivation email over several emails rather than emailing a large population of inactive subscribers all at once. Once you've sent the email you can remove anyone who didn't open the email or click on the reactivation link. Email lists, like house plants, need to be pruned regularly to keep them happy and healthy. Otherwise, you'll suppress new growth and suffocate them under the ever increasing weight of inactive contacts.


1. Make sudden and unexpected changes to the “From” email address you use to send emails. Your email address is your calling card, which helps people remember who you are and why they are receiving your emails while allowing them to easily recognize your email in their crowded inbox. If you have been sending emails from [email protected] and change it to [email protected], people may wonder who Sarah is, how she got their email address, and why she is suddenly emailing them. All of this could impact the overall engagement with your subscribers.

2. Change the email domain that you use to send emails. Inbox providers use a combination of machine learning algorithms and spam filters to decide which emails are accepted and which are rejected based on recipient engagement. One of the important factors in this decision is the sender reputation of your domain as brand new domains are treated especially suspiciously because of the prolific use by spammers to send malicious content. If you are sending emails from [email protected] and start using a sub-domain like [email protected], or even worse a cousin domain like [email protected], this can cause deliverability issues. 

3. If you start sending from a brand new sub-domain it will have no sending history and will be treated with greater suspicion. Using a sub-domain can help distinguish your email streams, such as separating your internal emails from your marketing or transactional emails. However, this needs to be carefully managed and email volume will need to be slowly ramped up when sending from the new sub-domain. As for cousin domains, these are largely used by phishers to spoof your email domain and trick unsuspecting people in disclosing sensitive information, and any legitimate company should stay well away from using them. During the busy holiday season, spam email traffic also increases, and we recommend avoiding any deliverability issues by using your well established email domain.  

4. Send emails to an old and inactive list which you haven’t emailed in more than a year. Many marketers don't realize that email addresses can become inactive in as little time as six months. Permission to send is not evergreen, and it expires as people forget how and where they signed up for your email list. Sending emails to an old list is a sure-fire way to have a low open rate, a high bounce rate and a high spam complaint rate, all of which are damaging to your sender reputation and will negatively impact the success of your future emails. If you do have an older list, you may consider sending emails to the most recent or active subscribers, such as those who signed up for your emails in the last 12 months or have shown some activity in the last six months.

Wrap up

The months leading up to the holidays are primetime to maximize your profits by capitalizing on the busiest spending period of the year. However, a well crafted email won’t do your company any good if your subscribers don’t see it because it never made it into the inbox.

Focusing on your active and engaged audience, sending targeted and relevant email content, being mindful of the subscriber experience—together, all of these healthy practices can strengthen your email deliverability while helping your emails land in the inbox more consistently. Good email deliverability means consistent inbox placement while providing engaging and interesting content that make your emails stand out, providing great results for your organization during the upcoming holidays.


About the Author

John Peters is a Deliverability Specialist for Emma and Campaign Monitor, and has been part of our Compliance and Deliverability team for seven years. He's a regular editor for our deliverability-focused blog posts.

More Content by John Peters

Want to engage your audience and grow your brand? Try Emma's robust easy-to-use product today.