When sending marketing emails, success depends on more than how many you send. What matters most is where your messages land. If your campaigns end up in spam or promotional folders, engagement and conversions drop sharply.
At Mailmonitor, we help marketers and businesses check email deliverability, improve inbox placement, and maintain strong sender reputations. This guide explains exactly how to measure these metrics and what actions you can take to achieve better inbox visibility.
What Is Email Deliverability?
Email deliverability refers to whether your emails successfully reach a recipient’s mailbox. It measures the percentage of messages that are accepted by the receiving mail server instead of being blocked, rejected, or bounced.
If you have a deliverability rate of 98%, it means 98 out of every 100 emails reached the recipient’s mail server. However, this does not mean they appeared in the primary inbox. Many of those emails could still be filtered elsewhere.
What Is Inbox Placement?
Inbox placement measures where those delivered emails end up. Placement tells you whether your message landed in the primary inbox, the Promotions tab, the Updates tab, or the spam folder.
A campaign can have high deliverability but poor inbox placement. According to Allegrow, even if 95% of emails are delivered, only 75% might appear in the primary inbox. The rest are hidden in less-visible folders, reducing open and click rates.
The goal of every sender is not only to deliver messages but to reach the main inbox, where they are most likely to be seen and opened.
How to Check Email Deliverability and Inbox Placement
The best way to understand your current performance is through email testing tools that measure both deliverability and placement.
Step 1: Choose Reliable Testing Tools
Select tools that test your campaigns across multiple inboxes and providers. These services help identify how your emails perform across Gmail, Outlook, Yahoo, and others.
- Mailmonitor: Provides both deliverability and inbox placement tracking.
Our platforms use a seed list, a controlled list of inboxes used to measure where your emails appear once sent.
Step 2: Send a Test Campaign
Once you have your tool ready:
- Send your email to the provided seed list.
- Wait for reports to show where your messages landed: inbox, spam, or other folders.
- Review additional diagnostics such as authentication results, content flags, and reputation signals.
Each one of these tools is different, and will provide you with different results. Follow the instructions on the listed websites to understand the outcomes of the tests and see what it means for your email deliverability.
Step 3: Analyze the Results
After testing, calculate your inbox placement rate. Divide the number of messages that appeared in the primary inbox by the total number of successfully delivered emails.
Look for:
- Providers where your inbox placement is low
- Authentication failures (SPF, DKIM, or DMARC)
- Spam content triggers
- Inconsistent sender reputation
These details help you identify what is keeping your campaigns out of the inbox.
How to Improve Inbox Placement
Checking results is only the first step. The next step is taking action. Below are key strategies to improve deliverability and inbox placement.
1. Authenticate Your Emails
Authentication builds trust with mailbox providers.
- SPF (Sender Policy Framework): Confirms that your sending IPs are authorized.
- DKIM (DomainKeys Identified Mail): Adds a digital signature to verify your messages.
- DMARC (Domain-based Message Authentication, Reporting & Conformance): Provides visibility and control over spoofing attempts.
Implementing all three helps ensure mailbox providers can verify you as a legitimate sender.
2. Maintain a Clean Email List
A clean list improves engagement and reduces bounce rates.
- Remove invalid or inactive contacts regularly.
- Segment subscribers by engagement level and target active recipients first.
- Avoid sending to purchased or outdated lists.
Healthy lists lead to stronger reputation and better placement.
3. Warm Up New Sending Domains and IPs
When using a new domain or IP address, start slowly. Send smaller campaigns and increase volume gradually. Mailbox providers monitor sudden spikes in activity and can interpret them as spam.
Gradual warm-up builds a reliable reputation over time.
4. Optimize Email Content
Even strong authentication can be undone by poor email content. Follow these best practices:
- Write clear and accurate subject lines.
- Avoid words and symbols often flagged as spam.
- Use a balanced text-to-image ratio.
- Always include an unsubscribe option.
- Encourage replies and engagement, which signal legitimacy.
Having your email content optimized ensures your emails end up in inboxes, and promotes clicks by your potential customers.
5. Monitor Sender Reputation and Blacklists
Your sender reputation directly impacts inbox placement. Watch for blacklisting or a rise in spam complaints, and make sure to remove issues early before they damage future campaigns.
You can check your sender reputation for gmail using Google’s Postmaster Tools. Microsoft also offers SNDS tools for ensuring Outlook deliverability. This works well for most clients, but in situations with more emails going to more inboxes, Senderscore also offers a free check, allowing you to see your sender reputation, and find ways to improve it.
6. Continue Testing and Improving
Inbox placement is not static. Regular testing ensures ongoing optimization.
After implementing improvements, run another test campaign and compare your new inbox placement rate. Continue refining authentication, content, and sending habits.
With continuous testing and tweaking your email optimization, your email campaigns will keep growing more and more successful, turning your delivered messages into conversions.
Key Takeaways
Checking and improving deliverability is essential for every email marketer.
- Deliverability measures whether your message arrives.
- Inbox placement determines if your audience actually sees it.
- Authentication, clean lists, and reputation management are essential for not being blacklisted or sent to spam.
- Regular testing ensures lasting success, and gets your emails seen by potential customers.
Mailmonitor brings all of these steps into one powerful platform.
Take the Next Step with Mailmonitor
- Run a deliverability test using Mailmonitor’s seed list feature.
- Review your inbox placement report by provider.
- Implement recommended improvements such as authentication setup and list cleaning.
- Re-test to confirm your improvements.
To see how Mailmonitor can improve your inbox placement and deliverability scores, contact our team for a personalized walkthrough. Start improving your inbox visibility today with Mailmonitor. Schedule a consultation to see exactly how your campaigns perform and how we can help you maximize every send.
