Key takeaways from Mailgun’s State of email deliverability 2025

Top takeaways from our email deliverability survey

We surveyed more than 1,100 senders across the globe, giving us insights into what businesses are prioritizing and where they may be falling short.

Every business wants as many of its messages as possible to reach customers and contacts. Companies rely on the email channel to deliver crucial communications to customers and contacts. So, it was no surprise that 78.5% of survey respondents rated the importance of deliverability an 8 out of 10 or higher.

Of course, simply saying something is important doesn’t always mean your actions match that point of view. While some senders can back up their belief in the importance of deliverability, others are either ignoring or are unaware of how to achieve inbox placement.

Digging deeper, you’ll find a mix of encouraging and concerning findings throughout State of email deliverability 2025. Here are several big-picture statistics in the report – good news on the left, bad news on the right:

New bulk sender requirements and deliverability

Towards the end of 2023, Google and Yahoo announced they planned to enforce new bulk sender requirements in the coming year. Even though the updated rules aligned with best practices most should have already been following, plenty of senders were freaking out a little bit.

That’s understandable. Sinch Mailgun’s consumer research found more than 70% of people in the, U.S., UK, France, Germany, and Spain have a Gmail account, and Yahoo Mail was the third most popular email client in our survey.

Gmail and Yahoo email addresses make up a large part of many contact databases. Struggling to reach those inboxes would no doubt have a negative impact. That’s why so many senders paid attention and joined our fireside chat with representatives from Google and Yahoo to learn more.

We used our sender survey to find out how email senders responded to the new requirements. Here are several key insights from the full report:

In the end, fewer than 25% of respondents noticed any deliverability problems they believed were connected to Gmail and Yahoo’s requirements. In fact, most of the senders we surveyed had positive feelings about the impact of the new rules.

While 14% of senders found the changes complex and confusing, a combined 63% said they were either necessary or good for the future of email. Just under 7% called them unnecessary.

When we discussed survey results with representatives from Gmail and Yahoo during Email Camp 2024, Dan Givol of Google had an interesting perspective on senders who found things complex and confusing. From his point of view, this was also a positive signal. If senders experienced challenges, at least it was a sign they were working to make the updates.

You can watch the entire Email Camp session with Dan Givol and Marcel Becker of Yahoo below. Plus, check out an Email’s not Dead podcast episode with many more insights and explanations from Marcel.

Good news for the future of email deliverability

So, did those stricter requirements create positive changes in the overall practices of emails enders? When comparing results from our previous deliverability report, it certainly appears that way in certain areas.

Increased DMARC adoption

DMARC (Domain-based Message Authentication, Reporting and Conformance) is the piece of the email authentication puzzle that has the most power to stop phishing schemes like email brand spoofing.

Mailbox providers have been encouraging more organizations to adopt this specification because it makes the inbox a safer place for users. Unfortunately, DMARC implementation hasn’t been a priority for some senders. That’s changing now that Gmail and Yahoo require DMARC when sending bulk email.

Our survey found there was an 11% increase among senders using DMARC in 2024 compared to 2023. Nearly 54% of all survey respondents say they’ve implemented DMARC compared to less than 43% in 2023.

There was also a 10% decrease in senders who were unsure about DMARC. That suggestsgrowing awareness. DMARC adoption is even higher among high volume senders.

Focus on monitoring spam complaints

The way mailbox providers use spam complaints to filter email hasn’t changed much since the ‘90s. But in 2024, Gmail and Yahoo were very clear about thresholds for spam complaints that can cause deliverability issues.

Bulk senders should try to maintain an overall spam complaint rate below 0.1% without ever reaching more than 0.3%. A spam complaint rate of 0.1% is one complaint out of 1,000 emails. If you’re above 0.1%, you’re in a danger zone. Once you hit 0.3%, it’s very likely your emails will be filtered into spam.

Sinch Mailgun’s Kate Nowrouzi was on the anti-spam team at AOL when they created the first report spam button for user-generated spam complaints. She says those are the same thresholds the industry has always used. So, while it’s nothing new, Gmail and Yahoo’s transparency brought attention to the need to keep spam complaints low.

Among those surveyed who made changes to comply with the new requirements from major mailbox providers, 37% said they began monitoring spam complaints. That was the second most common change after updating authentication. It means those senders are paying closer attention to the contacts who no longer want to hear from them as well as adjusting email campaigns that don’t resonate with their lists.

Regular list hygiene

Removing subscribers who mark your emails as spam is one practice that helps with email list management. But list hygiene also requires regularly scheduled checkups.

When it comes to maintaining a healthy contact database, the majority of senders in our survey are working to keep their email lists clean. Around 60% conduct list hygiene on a regular basis with more than a quarter doing it every month or more frequently.

Unfortunately, this also means that almost 40% of senders rarely or never conduct list hygiene, which will eventually lead to problems for email deliverability.

Sinch Mailgun’s email deliverability experts are big proponents of using sunset policies for list hygiene. This is when you segment or remove contacts who’ve stopped engaging with what you’re sending. We found that only 24% of senders use sunset policies.

Bulk validation of email lists is also a good best practice because it helps you identify and remove outdated contacts that create waste and drag down engagement rates.

Email deliverability challenges and misconceptions

While close to half of senders say avoiding the spam folder is an ongoing challenge, keeping lists clean and dealing with email bounce rates are also concerns.

Some of the results from our survey of email senders gave us the opportunity to clear up confusion and provide important reminders about how to support reliable inbox placement.

Mixing up delivery rate and deliverability

This might be the most shocking statistic in the entire report – nearly 88% of senders could not correctly define what the email delivery rate metric measures. Even though it was the second most common metric used to measure deliverability, it seems many senders don’t realize what it means to have a good delivery rate.

Only about 12% of those surveyed correctly identified the delivery rate as the percentage of emails sent that are accepted to any folder (including the junk folder).

In response to this confusion, Sinch Mailgun’s Renate Burns recorded a video explanation of the difference between the delivery rate and deliverability. She says that to measure deliverability, you need to look at other metrics such as opens, clicks, and even website visits. These metrics show that your emails reached the inbox and are doing their job.

Conducting inbox placement testing and reviewing the reports is another way to measure deliverability. In this case, you conduct tests that give you an expectation of where emails will land before you hit send on a big campaign or important email automation.

Shady list building tactics

No matter how many times we say it, there are still senders out there emailing people without obtaining proper consent. This bad behavior is one of the fastest ways to get yourself in trouble with mailbox providers. It will tank your sender reputation and your messages will end up in spam – which is where they belong because spamming is exactly what you’re doing.

It was good to see that more than 85% of senders have not purchased emails or scraped the web for contacts in the last two years. The problem is nearly 1 in 10 senders in our survey (9.4%) admit to this kind of shady list building.

There are some very clear reasons why adding emails to your list without obtaining consent causes major deliverability problems:

• It is how spam traps end up on your list, which can easily lead to a blocklisting.

• Your spam complaint rate will skyrocket, because you are literally spamming people.

• Your email engagement rates will be horrible, because these contacts never wanted to hear from you.

Interestingly, our research found high volume senders were even more likely to have purchased lists or scraped the web for email addresses in the last two years. Between 14% and 15% of those with monthly send volumes above 100k emails admit to using thiskind of list building.

Keep in mind, we didn’t survey spammers for this report. We asked legitimate email senders if they use these methods to build their lists. The temptation to quickly build a contact database with supposedly relevant emails is too much for some to resist. But the truth is, it will only hurt your sender reputation in the long run.

Sticking with a p=none DMARC policy

Even though DMARC adoption is increasing, senders must do more with it if they truly want stronger authentication that protects their domain and inboxes from bad actors. That’s because the DMARC policy many senders choose to use is just plain weak.

When Gmail and Yahoo announced their new requirements for 2024, they mandated the use of DMARC with a policy of p=none (as a minimum). The other policy options are p=quarantine and p=reject. Here’s what each one does:

For the second time, our report found the p=none policy is used most often. This policy is typically used during DMARC setup to test things out before beginning to enforce the protocol with a policy of reject or quarantine.

The problem is, since p=none meets the new requirement, too many senders are happy to leave things as they are. Our survey found that more than 25% of senders using a p=none DMARC policy plan to change over the next year. Unfortunately, more than 61% say they’ll only start enforcing DMARC if they are required to do so. Another 13% think meeting the requirement is enough.

Here’s the reality: Requiring DMARC with a policy of p=none was only the first step. Stricter requirements are coming. People who work for Gmail and Yahoo straight up told us this fact during webinars in which they were our guests.

Mailbox providers started with p=none because... well, baby steps. They just want DMARC implemented for now. But to get the most out of DMARC, you need a stronger policy. Eventually, mailbox providers tell us they will make p=reject the requirement.

Sinch Mailgun deliverability experts Jonathan Torres and Kate Nowrouzi have more on why p=none isn’t enough in the video below:

Opportunities to improve inbox placement

Let’s say you review some of the results in State of email deliverability 2025 and realize you’ve got room for improvement. Maybe you’re like some senders who were unsure how to answer questions about deliverability. Maybe you’ve been making some mistakes, or perhaps there are tools you need to start using to support better inbox placement.

The good news is, if you’ve got room to improve email deliverability, you also have room to increase your ROI from email. Here are some ways to get started:

• Email authentication: Show mailbox providers you’re a responsible sender by setting up SPF, DKIM, and DMARC to protect email recipients and your domain.

• Inbox placement testing: We found just 13% of senders use inbox placement tests to help them improve deliverability. It’s a powerful tool that can give you an edge.

• Monitor your reputation: 70% of senders say they don’t use free services like Google Postmaster Tools, but doing so can give you helpful insights. Another 53% don’t use blocklist monitoring.

• Maintain a healthy email list: If you’ve yet to adopt practices such as the double opt-in (DOI) or a sunset policy, they are game changers for building a clean list ofengaged contacts.

Navigating the complexities of reaching the inbox gets easier with the right deliverability tools. Mailgun Optimize is a complete suite of solutions. It includes everything from inbox placement reports to reputation monitoring and list cleaning tools. When you really need expert advice Deliverability Services from Sinch Mailgun connects you with dedicated technical account managers (TAMs) who help customize a strategy for your email program.