Email Deliverability Rates in 2024: The Highs & Lows

Next to realizing the commercial value of email, deliverability is the most significant element of marketing through email. Suddenly, you’re at the heart of what a successful email program is built on. Because if your emails do not land in the recipients’ inbox, you’re left with only great email copy and design—and zero ROI. 

You need to adopt standard email deliverability best practices to achieve good deliverability rates. But what is a good email deliverability rate? Does it vary from client to client and from ESP to ESP? If so, why? 

In this blog post, we’ll answer these questions and more. As an email marketing agency, these numbers have enabled us to position ourselves more strategically with a market-oriented and subscriber-friendly approach. 

In addition to following standard best practices, data-driven decision-making is central to our identity. 

You need to start with data to gain a solid understanding of the market. So let’s! 

• What Is A Good Email Deliverability Rate?
  
• Average Deliverability Rate for Marketing Emails
  
• Email Deliverability Rates for Different ESPs
  
• Email Deliverability Rates for Different ISPs
  
• Email Spam Statistics for Different ESPs
  
• Email Spam Statistics for Different ISPs
  
• Email Deliverability Report: Key Takeaways

What Is A Good Email Deliverability Rate?

Achieving a 100% deliverability rate is rare. Typically, a deliverability rate above 89% is regarded as good.

The numbers vary depending on the Internet Service Provider (ISP):

• Google: 95.54%
  
• Microsoft: 91.33%
  
• Yahoo: 81.33%
  
• AOL: 76%

The rates vary because different ISPs evaluate emails using different standards. The average email deliverability rate across Google, Microsoft, Yahoo, and AOL is 86.05%. 

“These big four (Google, Microsoft, Yahoo, and AOL) make up 87% of relative market share, which means 7 out of 8 emails are processed by one of these providers,” says Cai Ellis, SEO Manager at Email Tool Tester. 

Average Deliverability Rate for Marketing Emails

In the first quarter of 2024, the average deliverability rate for marketing emails stands at 83.1%. This means:

• Out of all the emails you send, 16.9% never reach the recipient’s inbox
  
• 10.5% of emails end up in the recipient’s spam folder
  
• 6.4% of emails are reported undelivered

So 1 in 6 marketing emails fail to reach the recipient’s inbox. Consider this scenario: 

Suppose you send out 600 emails to subscribers. According to the data, 100 emails will either end up in the spam folder or be reported undelivered. 

Further calculations show that out of 600 emails, 63 will land in the spam folder and 38 emails will be undelivered. In total, 101 emails won’t reach the intended inbox. 

Email Deliverability Rates for Different ESPs

Glock Apps conducted deliverability tests for 10 ESPs to determine the average inbox placement rate for the first quarter of 2024: 

• Mimecast: 76.8%
  
• AWeber: 58.1%
  
• HubSpot: 57.0%
  
• Klaviyo: 59%
  
• Amazon SES: 54.9%
  
• GoDaddy: 54.1%
  
• Mailgun: 53.8%
  
• Mailchimp: 51.9%
  
• Mailjet: 51.7%

• Dotmailer: 50.6% 

The average deliverability rate across these ESPs is 56.79%. 

Email Deliverability Rates for Different ISPs

As per research conducted by Glock Apps, here are the average email deliverability rates for the most popular inbox providers during the first quarter of 2024:

• Amazon Workmail: 92.40%
  
• GMX.com: 83.55%
  
• Exchange (Office 365): 77.43%
  
• Gmail (non-interactive): 66.38%
  
• G Suite (Google Workspace): 63.85%
  
• Zoho: 51.56%
  
• Gmail (legacy): 51.05%
  
• Outlook: 49.83%
  
• Hotmail: 48.83%
  
• Att.net: 46.45%
  
• AOL: 43.56%
  
• Yahoo: 43.08%

The average email deliverability rate for these email services is 63.08%. 

In contrast to the average inbox placement rate in the last quarter of 2023, mailbox providers such as Amazon Workmail, Office 365, and GMX saw an increase in their rates.

On the contrary, Gmail, Yahoo, AOL, and Outlook saw a decline in the first quarter of this year. According to the report, this could be attributed to new email sender rules implemented by Gmail, Yahoo, and AOL in February 2024, along with updated email filtering algorithms.

Email Spam Statistics for Different ESPs

Glockapps has provided the average spam placement rates for the top ten ESPs as follows:

• Mimecast: 4.6%
  
• AWeber: 9.4%
  
• HubSpot: 14.6%
  
• Klaviyo: 15.7%
  
• Amazon SES: 12.7%
  
• GoDaddy: 18.8%
  
• Mailgun: 16.9%
  
• Mailchimp: 19.0%
  
• Mailjet: 14.0% 

• Dotmailer: 20.2%

The average spam placement rate across these ESPs is approximately 14.59%. 

The difference between the best and worst spam placement rates for these listed ESPs is 15.6%. This is worth noting since standard deliverability best practices often overlook the importance of strategic ESP selection in addition to proactive sender reputation management and campaign optimization.

Email Spam Statistics for Different ISPs

The following is a list of the average spam placement rates for different ISPs in the first quarter of 2024:

• Amazon Workmail: 0.60%
  
• GMX.com: 4.62%
  
• Exchange (Office 365): 10.88%
  
• Gmail (non-interactive): 19.36%
  
• G Suite (Google Workspace): 21.36%
  
• Zoho: 3.97%
  
• Gmail (legacy): 30.95%
  
• Outlook: 38.32%
  
• Hotmail: 39.34%
  
• Att.net: 38.00%
  
• AOL: 44.76%
  
• Yahoo: 44.63%

The average spam placement rate across these ISPs is 24.68%. “The Spam placement statistics show that the average percentage of emails filtered out to Spam in the 1st quarter 2024 increased with almost all popular ISPs with the exception for Office 365, GMX, Zoho, and Amazon Workmail,” the report states. 

Certain inbox providers, like Gmail, prioritize user engagement and the perceived value of emails received. As a result, they may be less likely to flag emails as spam even when they contain typical spam indicators. This approach could explain why Gmail, along with other providers, has reported a higher spam rate in some cases. 

But at the same time, Glock Apps’ report indicates that the volume of emails sent per month did not significantly influence deliverability during the last quarter of 2023.

The apparent inconsistency only highlights the complexity of filtering algorithms. 

Gmail doesn’t prioritize user engagement over email volume; it enforces a specific sending limit. Even if emails are opened and engaged with, sending a large number can still raise red flags. 

“From a revenue standpoint, more emails = more money, but from a reputation perspective, the relationship is much more complicated. Revenue is a marketing goal, but not necessarily a deliverability one,” explains Alison Gootee, Compliance and Deliverability Enablement Principal at Braze. This highlights the ongoing balance between user engagement and email volume. 

Email Deliverability Report: Key Takeaways

In summary, here’s an overview of the numbers: 

• Good email deliverability rate: 89%
  
• Average email deliverability rate across Google, Microsoft, Yahoo, and AOL: 86.05%
  
• Average deliverability rate across the top 10 ESPs during the first quarter of 2024: 56.79%
  
• Average email deliverability rate for the most popular ISPs: 63.08%
  
• Average spam placement rate across the top 10 ESPs: 14.59%
  
• Average spam placement rate for the most popular ISPs: 24.68% 

Although an 89% email deliverability rate is considered good, it still results in 11% of emails not reaching the intended recipient. This discrepancy may seem insignificant for a small email list. For instance, with 50 subscribers, only 6 recipients might not receive the email, which is perhaps okay. However, when scaled up to a list of 5000 subscribers, missing 550 recipients is worrying. 

Scale matters. So aim for better deliverability. Significantly, last year, Australia and the UK reported the highest deliverability rates at 98.7% and 98.8% respectively. 

Note also the significant difference between ESP and ISP averages. Having a good ESP helps; but building and maintaining a good sender reputation with ISPs is critical. 

The overall spam rates are high. Both figures, 14.59% and 24.68%, indicate that a substantial amount of marketing efforts do not reach email recipients. 

The ideal spam complaint rate is 0.1% or less. Amazon Workmail is the sole service that maintains an average spam rate below that threshold. But here’s a snippet from a conversation between a frustrated Amazon WorkMail user and an expert, suggesting that WorkMail’s spam filter may occasionally classify legitimate emails as spam.

Image source

Read more: The Ultimate Guide On Everything About Email Deliverability

‘D’ for Deliverability, ‘E’ for Email: The Natural Order

Achieving email marketing success hinges on good deliverability. Adhering to email deliverability best practices is crucial to excel in email marketing.

For further information on deliverability, feel free to read what content fingerprinting is and how it affects your email deliverability. You can also catch what Scott Hardigree, founder of Email Industries, has to say on the fundamentals of email deliverability.