How did COVID-19 affect email engagement metrics in 2020 compared to 2019?
Michael Ko
Co-founder & CEO, Suped
Published 23 May 2025
Updated 15 Aug 2025
6 min read
The year 2020 brought unprecedented changes, rapidly shifting our lives and interactions into the digital sphere. As businesses and individuals adapted to lockdowns and new norms, email became an even more critical communication channel. It served as a primary means for updates, commerce, and connection, leading to a significant transformation in email sending behaviors and recipient engagement.
Many expected a complete overhaul of engagement metrics, but the reality was more nuanced. While some metrics saw notable increases, others remained stable or even declined, reflecting the complex and evolving relationship between senders and recipients during a global crisis. The patterns varied across industries and even within different phases of the pandemic.
My goal here is to break down how key email engagement metrics like open rates, click-through rates, unsubscribe rates, and complaint rates shifted in 2020 compared to 2019. Understanding these trends provides valuable insights into how recipient behavior changed and what that means for ongoing email strategy and email deliverability.
Email volume: a significant increase
One of the most immediate impacts was the sheer volume of emails being sent. With businesses moving online and individuals relying heavily on digital communication, email became the go-to channel for critical updates, service changes, and marketing efforts. Data from various sources confirmed this surge, with some reports indicating a significant increase in email sends compared to the previous year. For example, some platforms saw a 48% increase in email volume during the initial weeks of the pandemic compared to earlier in the year.
This uptick in volume wasn't uniform across all industries. While essential services, e-commerce, and communications saw substantial increases, other sectors experienced declines as their operations were halted. The shift highlighted email's adaptability and crucial role in crisis communication, but it also raised concerns about potential email fatigue, particularly as the initial novelty of pandemic-related communications wore off.
The increased reliance on email meant that many consumers were spending more time in their inboxes. This environment provided a unique opportunity for marketers, but it also placed a greater emphasis on relevance and proper segmentation to ensure messages cut through the noise. As we moved further into 2020, the initial rush of pandemic-specific emails began to subside, giving way to more generalized marketing messages, albeit at higher volumes than in 2019.
The surge in email volume
Many companies responded to the pandemic by sending more emails, often at an accelerated pace. This led to higher overall email traffic in 2020 compared to 2019. The rapid shift to digital for business operations and customer communication fueled this increase.
Adapting to the new normal
The initial surge was often followed by a period of adjustment. While volumes remained elevated, marketers began refining their strategies to avoid overwhelming subscribers, focusing more on targeted and relevant content rather than broad, frequent sends. This adaptation was crucial for maintaining engagement as the pandemic evolved.
Open and click-through rates: a mixed picture
When it came to open rates, 2020 saw a notable increase compared to 2019 for many senders. Initial reports from early in the year, such as those from Mailchimp, indicated a steady rise in both click and open rates as people sought information and connection. For instance, in Australia, open rates were 20.6% in 2020 versus 18.7% in 2019 according to Crazy Domains, showing a positive trend.
This increase was likely due to several factors: heightened public interest in updates regarding the pandemic, more time spent online by individuals working from home, and a general reliance on digital channels for information and entertainment. However, while open rates generally trended upwards, the story for click-through rates (CTRs) was different.
Despite higher open rates, many studies, including one by Omnisend, showed that click rates in 2020 declined by about 17.19% compared to 2019. This suggests that while people were opening more emails, they were not necessarily engaging with the content by clicking through. This disconnect could be attributed to information overload, a preference for quick consumption of updates without deeper engagement, or perhaps a lack of compelling calls to action amidst the crisis.
Industry variations were also significant. E-commerce saw increased engagement due to the shift to online shopping, while travel and hospitality faced severe challenges. The takeaway is that while eyeballs were on emails, the intent and action taken varied widely, underscoring the importance of monitoring multiple email engagement metrics.
Metric
2019 Average
2020 Average
Change (%)
Open rate
18.7%
20.6%
+10.2%
Click-through rate
2.8%
2.3%
-17.9%
Unsubscribe rate
0.2%
0.2%
0%
Complaint rate
0.02%
0.03%
+50%
Unsubscribe and complaint rates: new challenges
While open rates generally improved, the impact on unsubscribe and complaint rates presented a different challenge. Initially, some senders saw a small increase in unsubscribe rates, perhaps reflecting the overall digital fatigue as people were bombarded with information. However, this wasn't a universal or sustained trend across all industries or email types.
Complaint rates, on the other hand, became a more pressing concern for some. With the surge in email volume and the sensitive nature of the pandemic, many marketers struggled to strike the right tone. This led to instances of tone-deaf messaging that alienated subscribers, potentially leading to higher spam complaints. Higher complaint rates can negatively impact your sender reputation and lead to emails landing in the spam folder or even getting your domain added to a blacklist (or blocklist).
Understanding complaint trends
Monitoring complaint rates became crucial in 2020. While initial fatigue might have played a role, consistently high complaint rates often signaled a deeper problem with content relevance, audience targeting, or send frequency. Receiving too many complaints can severely damage your sender reputation.
Content Relevance: Ensure your messages are relevant to your audience's current needs and the global context. Avoid sending messages that appear opportunistic or insensitive.
Audience Segmentation: Target your emails precisely. Sending broad, generalized messages to everyone on your list, especially during a crisis, can increase complaints.
Frequency Management: Adjust your sending frequency to avoid overwhelming subscribers. More isn't always better, especially when attention spans are fragmented.
The increase in digital reliance and the volume of emails sent meant that Internet Service Providers (ISPs) were also adapting their filters. Maintaining a healthy domain reputation became even more critical. Senders who failed to adapt their content and frequency often saw their emails land in the spam folder, impacting overall deliverability regardless of global engagement trends.
Key takeaways and enduring lessons
The year 2020 served as a real-time stress test for email marketing strategies. While overall email volume increased and open rates saw a boost, the decline in click-through rates and the potential for higher complaint rates highlighted the importance of relevance, empathy, and careful segmentation. It became clear that simply sending more emails wasn't a sustainable strategy.
Looking back, the pandemic accelerated many trends already underway, pushing businesses to embrace digital communication more fully. It underscored the dynamic nature of email engagement and the constant need for marketers to adapt their strategies based on evolving recipient behavior and market conditions. The lessons learned in 2020 about communication in a crisis continue to shape best practices for senders today.
Views from the trenches
Best practices
Actively monitor engagement metrics, including opens, clicks, unsubscribes, and complaints, to quickly identify shifts in recipient behavior and adapt your strategy.
Segment your audience based on their engagement levels and preferences to ensure you are sending the most relevant content to the right people, reducing the risk of fatigue.
Prioritize email content that is genuinely helpful, informative, or entertaining to your subscribers, especially during periods of high stress or uncertainty.
Common pitfalls
Increasing email volume without corresponding increases in engagement, leading to lower per-email performance and potential spam complaints.
Failing to adapt messaging tone during sensitive periods, resulting in perceived insensitivity or opportunism, which can damage brand trust.
Neglecting to monitor unsubscribe and complaint rates, missing early warning signs of recipient fatigue or dissatisfaction.
Expert tips
Use A/B testing to refine your subject lines and calls to action, as recipient attention spans can fluctuate quickly.
Integrate email data with broader customer insights to understand the full journey and predict future engagement patterns.
Leverage DMARC reports to gain deeper insights into email authentication, delivery issues, and potential malicious activity impacting your brand.
Marketer view
Marketer from Email Geeks says they did their own analysis early on and saw a significant boost in opens for COVID-related emails, but this was likely before email fatigue set in.
October 2, 2020 - Email Geeks
Marketer view
Marketer from Email Geeks says they have internal benchmarks for their clients, but nothing has been publicly released yet because most are waiting until after the holidays.
