Testing email deliverability is essential to ensure your emails are reaching recipients’ inboxes rather than getting lost in spam folders. A solid deliverability test checks for various factors that impact inbox placement and can significantly improve your overall email marketing performance. Here’s how to test and improve email deliverability:

 1. Check Your Sender Reputation

Your sender reputation, influenced by factors like engagement rates, spam complaints, and sending practices, plays a major role in deliverability. You can use tools like:

• Google Postmaster Tools: Provides insights into your domain’s reputation and other factors.
• SenderScore (by Validity): Ranks your IP’s reputation on a scale of 0 to 100, with higher scores indicating better reputation.
• Microsoft SNDS: Helps monitor your sender reputation with Microsoft email services.

Regularly check your sender reputation to identify and resolve issues before they impact your deliverability.

2. Authenticate Your Domain

Authentication protocols help email providers verify that emails claiming to come from your domain are legitimate. Set up and test the following authentication protocols:

• SPF (Sender Policy Framework): Lists authorized mail servers for your domain to prevent spoofing.
• DKIM (DomainKeys Identified Mail): Adds a digital signature to emails, proving they were sent by your domain.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Provides instructions on how to handle messages failing SPF and DKIM checks.

Tools like MxToolbox or DMARC Analyzer can help verify that these are set up correctly. Proper authentication can prevent emails from going to spam and enhance your sender reputation.

3. Use Seed Lists for Inbox Placement Testing

Seed lists are a set of email addresses across various email providers that you send test emails to in order to see where your messages land (inbox, promotions, or spam folders). Popular inbox placement testing tools include:

• Mailgun Inbox Placement: Tests inbox placement across major email providers.
• GlockApps: Shows you if your emails land in the inbox, promotions, or spam for multiple providers.
• Litmus: Offers inbox placement testing and a suite of email testing tools.

By sending test emails to these addresses, you can gauge your deliverability across different email clients and make adjustments as needed.

4. Check for Spam Triggers in Content

Content plays a significant role in determining whether emails go to spam. Use tools like:

• Mail Tester: Analyzes the email’s content for spam trigger words, formatting issues, and more.
• SpamAssassin: Scans emails and assigns a “spam score” based on language, formatting, and links.

Avoiding common spam triggers like “Free,” “Urgent,” and “Act Now,” or using too many exclamation points and all caps, can help emails reach the inbox.

5. Ensure a Clean Email List

A high-quality, clean email list is essential for deliverability. Ensure you:

• Remove inactive subscribers: Identify those who haven’t engaged for a set period and re-engage or remove them.
• Validate email addresses: Use tools like NeverBounce, ZeroBounce, or Hunter to verify addresses before sending campaigns.

A clean list prevents hard bounces and keeps your engagement rates high, which signals to email providers that your emails are relevant.

6. Analyze Engagement Metrics

Email providers favor senders whose emails are regularly opened, clicked, and not marked as spam. To keep engagement metrics high:

• Use segmentation: Send relevant content to segmented lists based on interests or past interactions.
• Optimize send times: Use historical data to determine the best times to send.
• Encourage engagement: Add interactive elements like polls, surveys, and questions that prompt replies.

Regularly review open rates, click-through rates, and spam complaints to adjust strategies and improve deliverability.

7. Perform A/B Testing on Subject Lines and Content

A/B testing helps refine the content and format of emails, which can improve engagement and prevent emails from being marked as spam. Focus on testing:

• Subject lines: Test for length, personalization, and keyword choices.
• Preheader text: Optimize to align with subject lines and encourage opens.
• Content length and layout: Ensure the email is concise and visually appealing.

By consistently testing different variations, you’ll find the combinations that perform best, boosting deliverability and engagement.

8. Check Mobile Optimization

Many recipients will open emails on mobile devices, and poorly formatted mobile emails can hurt engagement. Ensure that:

• Your emails are responsive, adapting to various screen sizes.
• Font sizes, buttons, and images are optimized for mobile viewing.
• The email’s call-to-action (CTA) is prominent and easy to click on mobile.

Use testing tools like Litmus or Email on Acid to check how emails appear on different devices and adjust accordingly.

9. Monitor Blacklist Status

Being listed on a blacklist can severely impact deliverability. Regularly monitor your IP address and domain status on popular blacklists:

• Spamhaus: A major email blacklist used by multiple email providers.
• SURBL and URIBL: Check URLs within your emails to ensure they’re not blacklisted.
• MxToolbox: Scans multiple blacklists to ensure you’re not flagged.

If you find yourself on a blacklist, work with the blacklist provider to remove your IP or domain.

10. Implement a Preference Center

A preference center allows subscribers to choose the types of content they want to receive and how often. This can improve engagement and reduce spam complaints. A preference center might include options for:

• Email frequency (weekly, monthly).
• Content type (news, promotions, updates).
• Specific topics of interest.

By offering a choice, you’re more likely to keep subscribers engaged and less likely to have emails ignored or marked as spam.

11. Optimize Your Unsubscribe Process

Having a clear, easy unsubscribe option can improve deliverability by reducing spam complaints. Make sure your unsubscribe link is:

• Easy to find.
• Functional and promptly removes subscribers.
• Offers the option to reduce email frequency instead of unsubscribing entirely.

A smooth unsubscribe process keeps your list healthy and reduces the likelihood of frustrated subscribers marking your emails as spam.

12. Check Bounce Management Settings

Properly managing hard and soft bounces can prevent poor deliverability. Ensure that:

• Hard bounces (invalid addresses) are removed immediately from your list.
• Soft bounces (temporary issues like full inboxes) are retried a few times but removed if they continue.

Many email service providers (ESPs) offer automatic bounce handling, but it’s important to verify that these settings align with your deliverability goals.

13. Implement Throttling for Large Sends

Sending too many emails at once can cause issues with email providers. Throttling can prevent this by spacing out sends over time, especially for larger lists.

• Many ESPs offer throttling options for high-volume campaigns.
• Staggering send times can improve deliverability and prevent your IP address from appearing suspicious.

Throttling can be especially useful when sending to cold lists or newly added subscribers.

14. Track Email Deliverability Metrics in Real Time

Many ESPs offer deliverability dashboards with metrics on:

• Delivered vs. bounced emails.
• Inbox vs. spam folder placement.
• Engagement rates across providers.

Use this data to identify trends and address issues as they arise, allowing for prompt adjustments to maintain optimal deliverability.

 Conclusion

Testing and optimizing email deliverability involves a combination of technical setups, content best practices, and monitoring subscriber engagement. By following these steps and using the right tools, you can proactively address issues, improve inbox placement, and build a healthy relationship with subscribers and email providers alike.