Email deliverability statistics that show why inbox placement matters

Almost 27% and 10.5% — that’s the decline in the delivery rates for Office365 and Google Workspace, respectively. For sales and marketing teams, this means fewer delivered emails, lost opportunities, and wasted time and effort. Along with the standard updates, the reality is far from optimistic, especially for people launching their first campaigns.

So, what are the key email deliverability statistics to keep in mind? How do marketing or sales professionals ensure that they perform well? The following benchmarks will help you better understand your performance.

Top 10 email deliverability statistics to know

Let’s start with the email deliverability numbers so you understand why this topic is worth the fuss. 

Here are the top 10 statistics to help you ensure that your email marketing strategy considers all the risks:

1. 1 in 6 marketing emails failed to reach recipients’ inboxes in 2024.
2. 78.5% of email marketing specialists rate the importance of deliverability 8/10.
3. Global spam placement rates nearly doubled from Q1 to Q4 in 2024.
4. The average inbox placement for high-volume senders declined by 22.35%.
5. With an inbox placement rate of almost 76%, Microsoft became the toughest mailbox provider for email marketing teams.
6. Gmail saw almost a 5% decline in average email deliverability rates in Q1 2025 compared to Q1 2024.
7. Inbox missing rates — emails that weren’t delivered to either inbox or spam and were blocked or deferred — improved from 11.9% to 9.1%, meaning that email providers rejected fewer emails than the year before.
8. Almost 33% of email recipients feel disappointed when the company’s marketing messages land in spam instead of their inboxes. 
9. Furthermore, 10% of contacts lose trust in the brand if they see their emails in the spam folder.
10. Around 9.3% of specialists do not understand the sender reputation and its impact on email campaign results.

Email marketing is tough for many professionals, but mailbox providers’ standards and customers’ expectations brook no delays or exceptions. Deliverability remains crucial and directly impacts results — the topic for our next section. 

Impact of deliverability on key email marketing performance

How does email deliverability influence your campaign’s metrics? And how can you identify problems? 

Let’s review key metrics that hint at inbox placement issues:

• open rates: A rapid decline or near 0% open rates often indicates a deliverability problem. It can mean that marketing messages fail to reach inboxes and go straight to spam folders or bounce;
• click-through rates: 57.4% of teams use click and open rates to measure deliverability. A decline in both rates often means problems or unengaged subscribers;
• spam complaint rates: A good spam rate ranges from 0% to less than 0.3%. Higher spam rates indicate issues with email deliverability that worsen over time;
• bounce rates: Reducing bounces remains a challenge for 28.4% of professionals working with the email channel. While not all bounced emails are linked to deliverability, for example, when the email recipient’s inbox is full, some are a direct sign of issues.

It is safe to say that email deliverability is a driver of any campaign’s performance and that poor inbox placement can sabotage your efforts. Next, let’s explore a few tips to ensure that your campaigns are safe.

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Tips to improve email deliverability

Key elements of high deliverability

Some 59% of email professionals never monitor email blocklists for their domains and IPs. Furthermore, only 13% use inbox placement tests to check whether their marketing or sales emails land in spam or bounce. As a result, small overlooked essentials become a major problem.

So, what are the deliverability basics to keep in mind?

Email list hygiene

Around 39% of email marketers rarely or never clean their contact lists. While the percentage of those who admit to purchasing contact lists or doing scraping remains low — only 9.4% — email list hygiene should be mandatory. From engagement-based filtering to validation, this practice is a must.

What are the benefits of email list hygiene? Let’s take a look at the data from the Mailgun report:

• healthy sender reputation: Around 48% of survey respondents prioritize email list hygiene to keep their sender reputation high;
• increased engagement: Around 19% improved engagement with inactive or unengaged subscribers;
• decrease in spam rates: More than 17% of email marketing professionals improved their spam complaint rates.

(Source: Mailgun)

Proper authentication

Around 66% of professionals state that their organizations use SPF and/or DKIM for email authentication. The result? Inbox placement rates for finance reached 88%, and this is just the tip of the iceberg of the sender’s reputation impact.

Here is how you can improve deliverability with email authentication:

• maintain a strong infrastructure: Authenticate your emails with SPF, DKIM, and DMARC protocols and use testing tools to ensure you have a positive sender reputation;
• set up BIMI: Only 5.7% of email marketing specialists use BIMI, and 11% are working on it.  While this element may appear trivial, it can positively impact your sender reputation (according to 22.3% of specialists) and foster customers’ trust (as indicated by 30.3% of professionals).

(Source: Mailgun)

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How to improve deliverability with email authentication

Volume and frequency

A total of 18.6% of email marketing or sales professionals adjusted their sending frequency and volume when Google and Yahoo released new requirements. However, there are other deliverability pillars and ways to maintain a positive customer experience. 

Let’s take a look at how the inbox rate changed based on the volume of sent emails:

• 1–10k emails: The inbox placement rate improved by 0.8% in Q1 2025 compared to Q1 2024;
• 10k–50k emails: Unlike the previous option, inbox placement for these email senders declined by 5.2%;
• 50k–200k emails: Similarly, the inbox placement rate declined by 6.72%.

(Source: GlockApps)

The conclusion is obvious: the more emails email marketing or sales teams send, the more risks they take and deliverability becomes critical. 

Content quality

What about the content? Does it affect email deliverability? Good sales or email marketing should deliver value; otherwise, the chances of getting into spam increase exponentially. The reality, however, differs. 

However, poor, spammy content is a shortcut to losing your sender reputation and erodes your target audience’s trust and interest, in addition to increasing the risk of your emails landing in spam. Delivering quality is as important as proper configuration and sending frequency.

Deliverability benchmarks by industry

Different industries have different benchmarks. While one value is a good result for some, it can be a negative sign for the rest of the email marketing teams. 

To see the exact shift, I suggest that we review key deliverability metrics for the top 5 industries, according to Validity.

For professionals launching their first email marketing campaign, benchmarks are a way to assess how well they perform if there’s nothing to compare to. Additionally, knowing the average deliverability metrics can help you set realistic goals and detect weak spots.

Deliverability benchmarks by email provider

Now, let’s turn to the major mailbox providers. It is a fact that each email client has its own standards for senders. So how does deliverability vary? Let’s take a quick look at the key statistics.

It appears that Microsoft makes proper inbox placement most challenging for senders. It also has the highest spam and missing rates, so teams go the extra mile to ensure high email marketing deliverability.

At the same time, this highlights the importance of knowing the inbox provider’s standards and adjusting your campaigns to match them. Otherwise, all your efforts can go unnoticed.

Wrapping up

Deliverability ensures that your email marketing excels. It determines whether emails make it to prospects’ primary inboxes or go straight to spam and directly affects your campaign’s open and click rates and overall performance. The key to mastering deliverability lies in email list hygiene, proper authentication, volume, and content quality.

I hope this guide has helped you understand the reality of deliverability and the key practices to become a responsible sender. Good luck!