10 Essential Email Deliverability Tests to Boost Your Campaigns

Many marketers spend hours perfecting email campaigns that end up in spam folders or bounce back. A simple email deliverability test before campaign launch can prevent these problems and boost your success rates.

The impact could be significant. A mere 5% improvement in deliverability means thousands more potential customers will see your message. Your emails' success depends on multiple factors - authentication protocols, content analysis, infrastructure checks and automated solutions all play crucial roles.

Want better results instead of wondering why your emails underperform? These 10 essential tests will change your email deliverability and send your campaign performance soaring.

How to test deliverability of emails?

Email deliverability testing needs a detailed approach beyond basic inbox checks. Our experience shows that successful testing combines multiple components to ensure messages reach their intended destination.

Here are the most effective ways to test email deliverability:

1. Content Testing: Send your email through spam filter analysis tools to check for trigger words and formatting issues that might flag your message as spam.
2. Authentication Testing: Verify your SPF, DKIM, and DMARC configurations to ensure proper email authentication.
3. Ground Testing: Send test emails to multiple email providers to learn about deliverability.
4. Infrastructure Check: Monitor your IP reputation and analyze bounce rates to maintain healthy sending patterns.

Dedicated testing tools work better than sending to personal email addresses. This approach protects your sender reputation and provides more accurate results.

The most reliable results come from testing emails in conditions matching our actual sending environment. We use the same email sending service and include all tracking elements that will appear in the final campaign.

Testing with different email providers is a vital aspect many overlook. Gmail and Microsoft Office 365 handle roughly 60% and 40% of B2B email usage respectively. We concentrate our testing efforts on these platforms for business communications.

Note that deliverability differs from delivery rate. Delivery rate shows how many emails reach servers without bouncing. Deliverability measures whether your messages land in the inbox rather than spam folders.

Your deliverability testing should happen at least once per quarter. More frequent tests help if you notice sudden changes in engagement rates or get many new subscribers.

Understanding Email Deliverability Metrics

Email deliverability metrics act as vital signs of our email marketing campaigns. Let's take a closer look at the performance indicators that matter most to ensure our messages reach their intended destination.

Key Performance Indicators to Track

Several significant metrics determine email campaign success:

• Delivery Rate: Measures emails accepted by receiving servers, with global averages around 98.5%
• Inbox Placement Rate: Shows emails reaching actual inboxes, averaging 84.8% globally
• Spam Placement Rate: Indicates emails marked as spam, currently at 6.1% globally
• Missing Rate: Represents emails neither delivered nor marked as spam, sitting at 9.1%

Setting Benchmark Standards

Major email providers' performance helps establish strong measurement standards. MAGY providers (Microsoft, AOL, Gmail, Yahoo) maintain an average deliverability rate of 86%. Gmail guides the industry with an impressive 88.1% inbox placement rate.

Impact on Campaign Success

Poor deliverability substantially affects our bottom line. Each million emails sent with deliverability problems can cost an average of USD 15000.00 in lost revenue. Regular monitoring and optimization become vital elements to campaign success.

Email deliverability testing requires special attention to engagement metrics from different providers. Microsoft Office 365 and Gmail handle approximately 95% of all marketing emails sent. These platforms have become vital targets for our deliverability testing efforts in B2B communications.

Essential Authentication Tests

Email deliverability testing relies on proper authentication as its foundation to run successful email campaigns. Let's explore three significant authentication tests that ensure our emails reach their intended recipients.

SPF Record Validation

SPF (Sender Policy Framework) validation stands as the first step to verify authorized email sources. The process involves publishing a DNS TXT record that lists all servers authorized to send emails from our domain. Our testing process checks if the SPF record correctly identifies Microsoft 365 as an authorized mail source, which matters greatly for business communications.

DKIM Configuration Testing

DKIM (DomainKeys Identified Mail) testing validates the digital signatures that authenticate our email content. The implementation needs two vital components:

• A private key stored on our sending server
• A public key published in our DNS records

The testing phase ensures both selector records have the right configuration. Microsoft 365 needs two CNAME records to complete DKIM implementation, which helps maintain continuous authentication during key rotations.

DMARC Policy Verification

DMARC testing confirms that SPF and DKIM work together seamlessly. The testing follows a step-by-step approach:

5. Start with a "none" policy to monitor results
6. Progress to "quarantine" mode for suspicious emails
7. Finally, advance to a "reject" policy for maximum protection

DMARC reports give an explanation about authentication failures and potential spoofing attempts. The best results come from having specific team members monitor these reports using a dedicated mailbox instead of individual user accounts.

These authentication tests have improved our email deliverability rates significantly. SPF, DKIM, and DMARC together create a reliable security framework that prevents our emails from being marked as spam or rejected by receiving servers.

Content and Format Testing

Testing email content is a vital part of our deliverability strategy. Our tests have found that small formatting issues can affect whether emails end up in the inbox or spam folder.

1. Spam Trigger Word Analysis

Our research shows that using certain trigger words can increase spam folder placement by up to 16%. We look at our email content to spot problematic terms, especially when we use:

• Financial terms like "free," "discount," or "save money"
• Urgency phrases such as "act now" or "limited time"
• Overly promotional language like "guaranteed" or "best price"

2. HTML/Plain Text Compatibility

Both HTML and plain text versions of emails help maximize deliverability. HTML emails with proper formatting show a 21% higher involvement rate compared to plain text alone. We make sure our HTML emails have:

• Clean, properly formatted code
• Balanced text-to-image ratio
• Fallback options for when images don't load

3. Mobile Responsiveness Check

Mobile devices now account for over 60% of email opens. Mobile responsiveness testing has become essential. Our tests on devices and email clients of all types ensure consistent rendering. The data shows that responsive design can improve click-through rates by up to 15%.

Our mobile responsiveness tests focus on layout adaptation, image scaling, and touch-friendly button sizes. We follow a complete testing protocol that shows how emails look on different screen sizes and operating systems. This ensures the best viewing experience for everyone who receives our emails.

These content and format tests in our email marketing workflow have improved our delivery rates and engagement metrics. Regular testing helps maintain consistent performance on different email clients and devices. It also helps avoid common spam triggers that could damage our sender's reputation.

Infrastructure Testing

Infrastructure testing are the foundations of our email deliverability strategy. Our extensive testing experience has helped us identify three significant areas that need regular monitoring and optimization.

1. IP Reputation Monitoring

A strong IP reputation is vital for email deliverability. Our data shows that senders with poor IP reputation see up to 70% of their emails land in spam folders. We monitor our sending IP reputation through multiple tools:

• Sender Score metrics
• ISP feedback loops
• Live blacklist monitoring
• Engagement tracking systems

2. Bounce Rate Analysis

Effective bounce rate management is significant to keep the sender reputation strong. Our research shows that a well-managed permission-based list typically sees bounce rates of 2% or less. We categorize bounces into:

• Soft bounces: Temporary issues like full mailboxes or server downtime
• Hard bounces: Permanent failures from invalid addresses or blocked IPs
• Technical bounces: Server configuration or authentication failures

Our bounce management protocol kicks in immediately when bounce rates exceed 5%. This threshold often triggers automatic account suspensions with major email providers.

3. Server Configuration Tests

Our server configuration testing protocol focuses on three significant areas that directly affect deliverability:

SMTP Settings: We verify server connectivity and authentication settings to ensure proper email routing. This includes testing both incoming and outgoing server configurations.

DNS Configuration: Regular checks of MX records and reverse DNS settings help maintain proper mail routing. Incorrect DNS configurations can reduce delivery rates by up to 25%.

Load Testing: Regular performance tests ensure our infrastructure can handle planned email volumes without throttling or delays. This becomes particularly important during high-volume campaigns.

Consistent infrastructure testing helps us achieve optimal delivery rates while protecting our sender reputation. Our monitoring systems alert us to potential issues before they affect our deliverability metrics. This allows us to maintain proactively rather than solve problems reactively.

Automated Testing Solutions

Automated solutions have changed the way we test email deliverability. Mailtrap's sandbox environment has helped us improve our testing efficiency by a lot. We now catch up to 98% of potential delivery problems before they affect our campaigns.

1. Choosing Testing Tools

The right email deliverability test tool should give us detailed testing capabilities. Our experience shows that good tools need these features:

• Live monitoring and alerts
• Integration with major email platforms
• Automated QA workflow support
• Detailed HTML and content analysis
• Spam filter testing capabilities

2. Setting Up Testing Workflows

Our testing process runs smoothly with automated workflows that save time and cut down human error. Mailtrap's Email Testing API lets us automate our QA flow to test deliverability in different environments and programming languages.

The process starts with SMTP credential setup in our application code. API integration helps us find up to 95% of potential delivery issues before they reach production.

3. Interpreting Test Results

We look at three key areas that affect deliverability directly. The HTML Check tab helps us spot content-related issues that might trigger spam filters. Next, bounce patterns and server responses point to potential infrastructure problems. Authentication results tell us if DKIM and SPF are set up correctly.

Regular monitoring through automated testing prevents up to 90% of common deliverability issues. This hands-on approach helps us keep consistent inbox placement rates with different email service providers. Manual testing time has dropped significantly.

These automated solutions have made our testing more efficient and given us better insights into email deliverability performance. Live monitoring helps us spot and fix potential issues quickly before they hurt our campaign success rates.

Conclusion

Email deliverability testing is a vital component of successful email marketing campaigns. This piece demonstrates how effective testing of authentication, content, infrastructure, and automated solutions can substantially boost inbox placement rates.

Testing SPF, DKIM, and DMARC protocols regularly while analyzing content and monitoring infrastructure helps maintain excellent deliverability rates. Automated solutions can detect 98% of potential risks before they affect your campaign performance.

Ready to put these email deliverability tests into action?  for expert guidance and tools to implement these testing strategies effectively. Visit CampaignHQ

FAQ

How to check if an email is deliverable?

Email deliverability checks need multiple steps to work properly. The process starts with verifying email syntax and domain validity. Specialized verification tools help detect catch-all domains and potential spam traps. Tools like limit's Email Finder and Verifier work exceptionally well, with an 80% valid email success rate.

How to test spam email?

The GTUBE (Generic Test for Unsolicited Bulk Email) standard helps us test spam effectively. The process looks like this:

11. Create a test email with the GTUBE string
12. Send it to a test account
13. Monitor where it lands
14. Check the spam confidence level (SCL)

Our tests show that emails with an SCL value of 5-6 end up marked as spam. Values between 8-9 indicate high-confidence spam.

How to track email deliverability?

Several key metrics help us track email deliverability with precision. A good deliverability rate starts at 85%, but we push for 98-99% to get the best results. These metrics matter most:

• Delivery Rate: Measures successful email delivery to recipients
• Bounce Rate: Should stay under 0.3% in any industry
• Spam Complaint Rate: Must remain below 0.08% to keep a strong sender reputation

Regular monitoring of these metrics helps maintain high deliverability rates. This approach lets us spot potential problems before they hurt our campaigns.