Email Deliverability Checklist to Boost Your Inbox Success

If your emails don’t land in the inbox, your message doesn’t matter. Email deliverability is the gatekeeper of engagement—and every B2B marketer, consultant, or SaaS team needs a clear process for getting it right.

This email deliverability checklist gives you the exact steps to improve inbox placement, reduce bounce rates, and protect your sender reputation. Breaker can handle the technical side, but knowing the fundamentals helps you send with confidence.

Use this checklist to strengthen your email performance, protect your list, and make every campaign count.

Core Email Deliverability Checklist

To make sure your emails reach the right inbox, focus on the basics: proving you are who you say you are, keeping your list clean, watching how many emails bounce, and tracking where your emails land. These steps keep your sender reputation strong and your engagement high.

Verify Sender Authentication

Authentication shows email providers that you own your sending domain and that your emails are legit. Three main methods do this: SPF, DKIM, and DMARC.

• SPF (Sender Policy Framework) tells servers which IP addresses can send emails for your domain.
• DKIM (DomainKeys Identified Mail) adds a digital signature to your emails to prove they haven’t been faked.
• DMARC (Domain-based Message Authentication, Reporting & Conformance) uses SPF and DKIM results to decide how to handle suspicious emails.

Set these up properly to lower spam risk and stop phishing attacks. Without them, inbox providers might block your messages or send them to spam.

Maintain Clean Email Lists

Good email lists reduce the risk of sending to bad addresses. Regularly remove inactive people, bounced emails, and unsubscribes.

• Use list validation tools to catch invalid emails before sending.
• Segment your list to focus on engaged subscribers.
• Avoid buying email lists—they often include poor-quality contacts that hurt deliverability.

Cleaner lists raise open rates and reduce complaints. Automation tools can handle list hygiene while helping you attract real B2B leads.

Monitor Bounce Rates

Bounce rates show how many emails fail to reach subscribers. There are two types:

• Hard bounces: Permanent failures, like a non-existent address.
• Soft bounces: Temporary issues, like a full mailbox.

High bounce rates signal poor list quality or sender problems and harm your reputation. Keep your bounce rate under 2%. Remove hard bounces immediately and watch soft bounces closely. This prevents inbox providers from flagging your domain as risky.

Track Inbox Placement

Not every email lands in the inbox—some go to spam, promotions, or other folders. Knowing where your emails end up helps you adjust your content, sending times, and frequency.

• Use tools to measure inbox placement rates.
• Test different subject lines or sending domains.
• Keep your content relevant and avoid spam triggers.

Smart delivery systems improve inbox placement so your newsletters reach the right B2B contacts. Monitoring placement lets you spot issues early and improve subscriber engagement.

Sender Reputation Best Practices

Your sender reputation shapes how email providers treat your messages. Keep it strong by warming up new domains carefully, watching blacklists often, and sending at steady volumes.

Warm Up New Domains

When you start sending from a new domain, send small batches of emails and gradually increase the volume over a few weeks. This helps email providers see your domain as trustworthy.

Send to your most engaged subscribers first. Their opens, clicks, and low bounce rates build positive signals. Avoid sudden spikes in sends, which can trigger spam alarms.

Track your progress by monitoring open rates and bounce rates. If either drops or spikes, slow down your sending speed.

Monitor Blacklists

Check if your IP address or domain appears on email blacklists. Being listed can cause your messages to get blocked or sent to spam. Use free tools to scan popular blacklists weekly.

If you find yourself on a blacklist, act quickly to identify the cause. Common reasons include sending to invalid email addresses or receiving spam complaints. Fix these issues, then request removal from the blacklist.

Keeping your lists clean and avoiding spam traps prevents blacklist issues. Automating list validation saves time and helps protect your sender reputation.

Maintain Consistent Sending Volumes

Avoid big spikes or drops in the number of emails you send each day. Sudden changes look suspicious to email services and hurt your reputation. Instead, send steady volumes week to week.

If you need to send more emails, increase slowly—about 10% more weekly—while keeping your engagement stable. Consistency builds trust and helps inbox placement.

Match your sending volume to your list size and engagement levels. If you have fewer active subscribers, keep sending smaller to maintain high open and click rates. 

Optimizing Email Content

To get your emails read and boost engagement, focus on clear subject lines, avoid words that trigger spam filters, and balance your images with text.

Craft Relevant Subject Lines

Your subject line is the first thing subscribers see, so it needs to grab attention fast. Use concise language that clearly shows the email’s value or purpose. Avoid vague phrases like “Don’t miss out,” and instead be specific, like “5 ways to boost B2B sales this quarter.”

Personalize subject lines by including the recipient’s name or company to increase open rates. Keep subject lines under 60 characters to ensure they display fully on most devices. Avoid using all caps or excessive punctuation, which can seem spammy and turn off readers.

Test different types of subject lines to learn what works best with your audience. Automation simplifies this process, so you can focus on what drives results.

Avoid Spam Trigger Words

Certain words are red flags for email filters and can send your message straight to the spam folder. Common spam triggers include terms like “free,” “guarantee,” “urgent,” and “act now.” These make your email look like a sales pitch.

Use straightforward language that matches your audience’s expectations. For example, replace “free” with “no cost” or explain the benefit clearly without hype. Avoid too many exclamation marks and excessive capitalization.

Check your email through spam testing tools before sending. Maintaining a clean list and letting subscribers opt in naturally also reduces spam risk. 

Use Proper Image-to-Text Ratio

Emails heavy with images and little text can trigger spam filters or fail to engage readers. Aim for a balance where text makes up about 60-80% of your email content. This helps your message come through clearly, even if images don’t load.

Use images to support your content, like a logo, chart, or product photo, not as the whole message. Include descriptive alt text for each image to improve accessibility and provide context if images don’t display.

Compress images to keep your email size small. Simple layouts with clean fonts and a clear call to action work best for B2B newsletters aiming to grow an engaged subscriber list.

Technical Deliverability Factors

To get your emails into inboxes, focus on key settings and security measures. These ensure your messages look trustworthy to email providers and avoid spam filters.

Configure SPF, DKIM, and DMARC

SPF, DKIM, and DMARC are email authentication protocols that prove your messages come from you.

• SPF (Sender Policy Framework) lets servers know which IP addresses can send emails on your domain's behalf.
• DKIM (DomainKeys Identified Mail) adds a digital signature to your emails. This confirms the email hasn’t been changed during delivery.
• DMARC (Domain-based Message Authentication, Reporting & Conformance) tells receiving servers how to handle emails that fail SPF or DKIM checks.

Set these up in your domain’s DNS settings. They protect your domain from spoofing and increase trust with inbox providers. Use online tools to test your setup before sending to your whole list.

Use a Dedicated IP Address

A dedicated IP means only your email traffic uses that IP, unlike a shared IP, where many senders share the same address.

This helps you control your sender reputation. If you share an IP with spammers, your email deliverability suffers. But a dedicated IP requires sending enough email volume consistently to build a good reputation.

For smaller senders, a shared IP with a strong reputation might be fine. For growing newsletters or B2B campaigns, a dedicated IP can help maintain better inbox placement and avoid delays.

Implement TLS Encryption

TLS (Transport Layer Security) encrypts your emails during transit. This keeps your data safe from interception.

Most major inbox providers expect TLS, so not using it can reduce your delivery rates. Ensure your mail server supports TLS and forces its use where possible.

By enabling TLS, you protect sensitive information and build trust with your recipients. This is especially important for B2B emails that may contain confidential content.

Automated tools can manage these technical settings so you can focus on list growth and engagement.

Performance Monitoring and Continuous Improvement

To keep your emails landing in inboxes and engaging readers, watch how they perform and make ongoing tweaks. Tracking delivery stats, gathering subscriber opinions, and testing across email apps help you spot issues and improve results.

Institutional Insights on Bulk Email Behavior

Research from a Cornell University study examining large-scale organizational emails revealed that high open rates did not always indicate meaningful engagement—many recipients opened messages briefly before deleting them.

This emphasizes that clean lists, relevant content, and controls on email frequency are just as important as technical setup when safeguarding inbox placement.

Analyze Delivery Reports

Look at delivery reports every time you send a campaign. Focus on key metrics like bounce rate, open rate, and click-through rate. A high bounce rate means some addresses are invalid or flagged as spam.

Watch sender reputation scores and spam complaint rates. If complaints rise, adjust your content or frequency. Use this data to optimize subject lines, send times, or your list cleaning process.

Solicit Subscriber Feedback

Your subscribers know best what they want. Send short surveys or feedback emails asking what content they find valuable or what they want less of. Keep questions simple and focused, like rating email frequency or preferred topics.

You can also use direct replies to collect insights. Positive feedback helps reinforce what works. Negative feedback highlights areas to improve or reasons to unsubscribe. Acting on real subscriber input reduces churn and boosts engagement.

Make feedback a regular part of your email routine. It keeps your list fresh and aligns your messaging with reader needs.

Test Across Major Email Clients

Emails look different on Gmail, Outlook, Apple Mail, and others. Test your emails on the top clients your audience uses to ensure formatting, images, and links work well everywhere.

Use tools or platforms to preview your campaigns before sending. Check that your calls to action are clear and that buttons work on mobile devices, too. Fix issues like broken links or layout shifts immediately.

Regular testing helps avoid deliverability problems caused by poor email rendering. It also improves user experience, which supports higher open and click rates.

Better Deliverability Starts with a Smarter Checklist

Great content means nothing if your email never hits the inbox. A strong deliverability strategy keeps your messages visible, your reputation intact, and your audience engaged.

Use this checklist to audit your process, protect your sender identity, and improve the performance of every campaign. Whether you’re building a list or scaling your reach, Breaker can help manage the technical details. This way, you can focus on strategy, not firefighting.

Start optimizing your deliverability today to reach the inbox—not the spam folder.

Frequently Asked Questions

Improving email success means focusing on your open rates, avoiding spam filters, and using the right tools to monitor performance. You also need to understand your deliverability score, apply strong strategies, and authenticate your emails to boost overall results.

How can I improve my email open rates?

Use clear and engaging subject lines that speak directly to your audience. Personalize your emails by including the recipient’s name or relevant content. Send your emails at times when your subscribers are most active.

What are the best practices to avoid spam filters?

Avoid spammy words and phrases in your subject and body. Keep your email list clean by regularly removing inactive or invalid addresses. Use a consistent sending schedule and authenticate your emails with proper protocols.

Which tools should I use to monitor my email deliverability?

Look for tools that track bounce rates, open rates, and spam complaints. These help you spot problems early. Some platforms handle this automatically, so you can focus on growing your list and sending engaging content.

How do I interpret my email deliverability score?

A higher score means your emails are reaching inboxes, not spam folders. If your score is low, check your sender reputation, email content, and list quality. Use the score to guide improvements and track changes over time.

What strategies can increase my email deliverability rate?

Send relevant content that your audience expects and wants. Keep your list updated and avoid buying email lists. Segment your subscribers to target different groups with tailored messages. Automate validation to protect against invalid addresses.

Can you suggest ways to authenticate my emails for better deliverability?

Set up SPF, DKIM, and DMARC records for your domain. These protocols show email providers that your messages are legitimate and help improve inbox placement.