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The importance of deliverability analytics during the holiday season

Optimize your email campaigns and ensure engagement during festive seasons with deliverability analytics to prevent list fatigue.
Marketer looking at deliverability analytics during the holiday season.

During busy and festive seasons, marketers may experience greater deliverability variations than during quieter periods.

We don’t recommend taking risks with your data ahead of the busy period – as recently discussed in our festive spam traps blog post. Expanding your sending volumes and engaging with less active recipients can be a great opportunity for your brand. However, it’s important to approach this strategically and keep a close eye on the results of every campaign you send. This will allow you to make data-driven decisions and ensure that your efforts are effective in re-energizing your audience.

In this blog post, we will delve into email deliverability analytics. We will set some expectations for what you may see over the next few months and discuss the factors that affect email deliverability.

Negative metrics are critical

Email marketers have long relied on opens and clicks as the primary indicators of engagement. However, email has advanced to the point where images are now pre-cached by many email providers such as Gmail, Microsoft, and Apple. 

Additionally, anti-malware filters have become more sophisticated and may click through links to ensure they are safe for recipients, which means that these clicks may not necessarily represent human interaction. As a result, relying solely on traditional open and click metrics is no longer sufficient to accurately measure engagement.

Let’s look at negative metrics. While interest can only be indirectly measured, senders are directly informed by recipients (and mailbox providers) when their expectations are not met.

Unsubscribes vs complaints – useful but not equal

If you are reaching out to your older lists, expect an increase in unsubscribes and complaints (recipients marking your email as junk or spam). You can learn more about your subscriber’s journey by analyzing where these interactions happen. If contact drops out at the beginning of their lifecycle, weak data capture or poor expectation setting are key. If you lose them mid life-cycle, content and frequency play an important role.

A healthy list interaction will show higher unsubscribe than complaints. Unsubscribes do not affect your sender reputation. However, if contacts mark your emails as junk or spam, it will have a heavily negative impact. If you’re seeing more complaints than unsubscribes, then this may be an indicator that your unsubscribe journey needs some attention.

Soft bounces

During the seasonal period, you may notice an increase in soft bounces. A sharp spike is likely to indicate that there’s a problem with the list you are targeting, especially if you haven’t sent it recently. However, a gentle increase overall could be due to the whole email ecosystem being put under strain and a healthy email program will recover.

Soft bounce data can provide insights into how mailbox providers view your emails and what impacts email deliverability. It’s important to note whether the bounces are temporary or persistent and whether they occur on a single domain or multiple domains. Focusing on these details can help optimize your email campaigns and enhance your deliverability rates.

If the volume of soft bounces has affected engagement (opens, clicks, etc.) that indicates the mailbox provider may be junking your mail. Tweak the contacts you are targeting and reduce the frequency at which you reach out to less engaged and unengaged recipients.


It’s important to remember that email is a two-way communication channel, so you should be checking the replies to your emails. The positive side of replies is that you can see real interaction here; a snapshot into what affects email deliverability. A healthy list will likely receive some questions and comments in amongst the out-of-office replies.

You can use these to see what contacts really think about your emails, and from there work out if you have any weaknesses in other areas such as poor data capture or expectation misalignment at the point of collection.

It’s essential to keep an eye on replies during the festive period, as they’ll be a great indicator if you’re over-sending to your recipients. Failing to check replies could also mean missing questions from your customers about products or purchases, leading to lost sales or bad reviews for poor customer service.

Open rates

An open simply tracks the downloading of a pixel. It’s never been an accurate metric of a real open, because this is not the same as actual human eyes reading your emails.

It’s important to keep track of more than just open rates when it comes to email marketing. Metrics such as click-throughs, replies, and purchases can also be valuable indicators of your campaign’s success. It’s a good idea to monitor these metrics over time to spot trends and identify what’s working and what’s not. By doing so, you can address any potential challenges and optimize your email marketing strategy for maximum effectiveness.


Clicks continue to be an important indicator of how engaged recipients are and whether emails have landed in the inbox or not. With the introduction of iOS 17 and Link Tracking Protection, digital marketers have started to question the future of click-based engagement tracking.

Pay attention to trends in clicks over time, especially if re-mailing to non-openers during the festive period. Clicks can be viewed holistically along with open rates, measuring website traffic, and actual purchase data. This versatile insight can indicate whether sending again to contacts who didn’t open the first time is actually worth the revenue, or whether it carries a high risk of damaging your sending reputation and could jeopardize the success of future sends.

As with open rates, B2B senders should now have enough data to know what impact non-human interaction (NHI) has (if any) on their click through rate reporting. If you are suddenly seeing NHI where previously there was none, this is a useful negative metric. Poor reputation is associated with an increase in filters checking links, so it could be an indicator that something is awry with your strategy.

Analyze your deliverability analytics to avoid list fatigue

Recipients can be overwhelmed with email during the holidays, and they may not engage with content as they normally would. By increasing the volume you send, you can decrease the average list engagement – this is list fatigue. 

Mailbox providers are also under heavy load receiving the influx of seasonal emails. An increase in volume coupled with a decrease in engagement is more likely to be interpreted as a sign that your emails don’t belong in the inbox. This can result in a further decline in the success of your emails, even when sending relevant content such as promotions to encourage interaction.

It’s a good idea to analyze the reporting data for your emails, but if you want to take it to the next level, our Deliverability Perspective package provides you with access to more comprehensive inbox placement data, including seeding. This package provides a wealth of information that can help identify potential issues, such as list fatigue, during critical business sending times.

Please get in touch if you’re interested in any of our deliverability products – or if you need any assistance with inbox placement over the festive season.

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