Skip to content
Share
Explore
Email Deliverability: 10 Steps to Reach the Inbox
There is hardly a company that does not engage in email marketing today. Email is still the easiest way to reach out to the clients with special offers, news, or updates. Transactional messages after the account registration, password update, or online purchase are also delivered via email.
Despite its apparent simplicity - write an email and hit “Send” - email communication has hidden pitfalls. Email is effective when it lands in the Inbox. There is nothing more frustrating for an email author if a well-crafted message doesn’t reach the target recipients because it’s filtered out to Spam or blocked.
For companies whose business depends on email marketing, it’s important to understand the basics of email deliverability and the practices of how to send emails in the right way in order for them to get opened and read by the recipients.
Email Delivery vs Email Deliverability: What’s the Difference?
Working side by side with email marketers for many years, I often notice that senders don’t actually understand the concept of email deliverability and its importance.
Email deliverability is often perceived as a synonym of email delivery. While both stand as the metrics to track email campaign performance, they measure different things.
Email delivery refers to whether or not the receiving server accepted the message and delivered it to the recipient, regardless of the folder (Inbox or Spam).
Email deliverability refers to whether or not the receiving server delivered the email to the recipient’s Inbox. In short terms, email deliverability is the Inbox placement.
Let’s look at the two reports below
For both messages, the email delivery rate is 100%
For Message #1, the email deliverability rate is 46,8%.
For Message #2, the email deliverability rate is 100% (Tabs mean different Inbox tabs, like Promotions).
Email placement results for Message #1
Email placement results for Message #2
Although both metrics are important, the email deliverability rate provides a better understanding of how the email campaign will perform and often answers the question of why the email open rate drops or the ROI is low.
Is It Possible to Measure Email Deliverability?
Tracking the email delivery rate has become an email marketing standard, and many email service providers offer that metric. All the messages, which did not bounce, are considered delivered.
When it comes to tracking email deliverability, it’s not as simple as it seems to be, primarily because email receivers don’t send signals about where they will place the email. After the email is accepted for delivery, it’s subject to various email filters, which will determine the destiny of the message.
Many email senders stay unaware of email deliverability issues and only learn about the Spam placements from their recipients’ feedback.
However, utilizing email testing tools like , you can get visibility on email placement. You send your message to a test list, and in a few minutes, you receive a report with granular data across different inbox providers. This allows you to estimate your potential email deliverability and pinpoint Spam placement issues with particular ISPs.
GlockApps email placement report
10 Steps to Ensure High Email Deliverabilit
As I mentioned above, when an email reaches the receiving server, it passes through a set of filters, which determine where the email lands. If the recipient doesn’t set custom rules on how to treat the emails coming from a particular email address or domain, this decision is made based on evaluating various factors related to the sender.
Here is a list of best practices that can help you to achieve high deliverability:
1. Send to a Targeted List.
The quality of the email list determines the success or failure of your email campaigns. Targeted lists bring more positive actions and fewer negative reports. It matters as inbox providers notice how the recipients react – more emails stay unopened or are reported as spam, more emails start going to “Spam” in the future. On the other hand, positive actions (opens, clicks, replies, forwards) favor a higher Inbox placement rate.
2. Maintain a Good Email List Hygiene.
This involves excluding hard bounce emails, unsubscribed users, and complaining recipients from email campaigns. Reputable email service providers handle this for you. If you operate your own mail server, you should have a tool to process bounce emails and unsubscribe requests. You should also sign up for freeback loops with ISPs to receive notifications about spam reports on your emails.
3. Try Better Email List Segmentation.
Analyze the statistics on your email opens and clicks for the last year and separate the recipients who have not reacted within the last six months. Consider creating a re-engagement email campaign for this inactive group. Exclude those who don’t respond from your actual list.
Additional segmentation criteria may be suggested by the recipients’ data collected during signup. You can look at their interests, preferences, previous purchases or downloads, and personal information to understand how you can target them better.
4. Authenticate Your Emails.
Setting up SPF, DKIM, and DMARC records for your sending domain is required by email providers. Email authentication allows email receivers to confirm the legitimacy of the sender and the integrity of the message. Thus, inbox providers have more trust in authenticated emails, while unauthenticated ones can be sent straight to the Junk folder or rejected outright.
Email authentication is implemented by publishing TXT records in DNS. Reputable email service providers instruct domain owners on how to add SPF, DKIM, and DMARC records and provide the records values to be published.
5. Monitor Your Domain and IP Reputation.
When a domain or IP address is reported to send spam, this doesn’t stay unnoticed by anti-spam organizations. IP addresses and domains known to send unsolicited emails are added to different blacklists. Email receivers may refer to public blacklists in order to verify the sender’s reputation.
To keep email deliverability high, it’s important to have a clean email domain and IP address. Email service providers use shared IP pools, which gives you limited control over the IP reputation. However, if you operate a dedicated IP address, you should test it and your sender’s domain against public blacklists and submit removal requests timely if a listing happens.
The tools like MXToolbox or GlockApps can help you with IP and domain monitoring. Almost instantly, you will receive a report with your IP or domain status.
Once authentication is configured, it’s important to monitor your domain for issues or unauthorized sending sources continuously. Tools like help understand DMARC reports more easily with clear dashboards, smart alerts, shareable projects, and built-in AI analysis, making it simpler to detect authentication problems on time.
6. Warm Up a New Domain and IP Address.
Sending a high volume of emails from a newly acquired domain or IP is a bad practice that leads to a lot of emails to be filtered out. Instead, a new IP and domain should be subject to a warmup process. During a warmup phase, you start with a small volume and gradually increase it every day. This may take weeks or months, depending on your desired monthly volume.
You can utilize a warmup tool to automate the IP and domain warmup or manually split your email list and send to each segment daily.
7. Use Subdomains to Separate Email Traffic.
Different types of emails, such as transactional, marketing, and newsletters, should be sent from different domains and IP addresses if applicable. Marketing messages generate more unsubscribes and spam reports by their nature, which then impacts the domain and IP reputation.
A good practice is to set up subdomains on your main domain and separate different email streams by subdomains. This way, the reputation of one domain will not affect the other, and the deliverability of highly important transactional emails will not suffer.
8. Keep Email Volume and Frequency Consistent.
Consistency helps to establish and maintain a sender reputation with inbox providers. Establish sending patterns based on your subscribers’ preferences or internal needs and follow them.
Does email volume matter for deliverability? According to our latest , for senders with 1,000K+ emails per month, the average Inbox rate increased for all major Inbox providers, with the biggest change for Gmail (+20%) and Office365 (+19%) in quarter 4, 2025. At the same time, for senders with 1-10K emails per month, the average Inbox rate with AOL and Yahoo increased by 24% and 26%, respectively.
Email Statistics 2025: Average Inbox Rates for Senders with 1 – 10K Emails per Month
(Q4 vs Q3)
Focus on the relevance of emails and consistent sending regardless of the volume. It is possible to increase outbound traffic on special occasions and in peak seasons, but such campaigns should be well planned.
9. Track Email Metrics
As recipients’ actions directly impact your ability to send emails to the inbox, understanding the level of user engagement with your emails is important
Is your content relevant? Is your list active? Does your unsubscribe process work? You can have answers when analyzing your email tracking statistics. Email service providers typically offer them in your account, including your bounce rate and user-reported spam rate.
Google recommends staying below 0.1% and never hitting 0.3%. Yahoo requires keeping a spam rate below 0.3%. As additional sources of information, you can use the tools like Google Postmaster, Yahoo Sender Hub, and Microsoft SNDS to monitor important domain metrics with these providers.
10. Test Your Deliverability.
In the environment, when inbox providers introduce new sender requirements and update their filtering algorithms, it is important to regularly test your email placement to be aware of reputation and deliverability issues.
Deliverability testing helps to determine email content and domain configuration issues, Spam placements, and undelivered messages. Testing will also allow you to identify email throttling problems when the emails are delivered hours after they are sent.
An at GlockApps returns a detailed report within a few minutes. The tool checks the IP and domain reputation, email spam score with major spam filters like SpamAssassin, Barracuda, Microsoft EOP, and Proofpoint, and email placement (Inbox, Primary/Promotions, or Spam) with various providers across the world.
The report also provides a detailed content analysis, including the level of HTML support by different devices. Actionable recommendations on how to improve deliverability are included in the report.
Conclusion
The term of email deliverability refers to the percentage of emails delivered to the users’ inboxes, while email delivery counts all delivered emails regardless of their placement.
Email deliverability is a more granular metric that reflects the actual sender reputation. Regular testing of your email deliverability helps you to estimate how well your emails perform and identify possible issues decreasing your Inbox rate.
By properly managing your email list, establishing sending patterns, configuring email authentication records, and regularly monitoring your domain metrics, you can keep a high sender reputation and ensure good email deliverability.
–
AUTHOR BIO
Julia Gulevich
Head of Customer Success at GlockApps | Email Deliverability Expert | 16+ Years in Email Marketing
Want to print your doc?
This is not the way.
This is not the way.
Try clicking the ··· in the right corner or using a keyboard shortcut (
CtrlP
) instead.