Is your email message ready for distribution? After working to craft compelling content and pair it with eye-catching design elements, you probably think so. But have you considered deliverability? Before you hit send, you need to know that your message is heading for the inbox, not the spam folder or promotions tab.
This pre-send checklist will help you ensure your campaign will land in the inbox. Learn what technical and content-based checks to complete, how to use an email deliverability tester for ESP users, and why skipping these steps could cost you opens, clicks & revenue.
1. Authenticate Your Domain
Before anything else, verify that your emails are coming from you. Authentication protocols like Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM) & Domain-based Message Authentication, Reporting & Conformance (DMARC) tell inbox providers that your email is trustworthy. Without these, your messages could be blocked or flagged as phishing attempts, even if your content is squeaky clean.
SPF confirms which servers are allowed to send emails on your behalf. DKIM attaches a unique digital signature to each email to prove it wasn’t tampered with in transit. DMARC adds a policy layer that tells receiving servers what to do if SPF or DKIM checks fail. Together, these protocols significantly improve your sender credibility and help protect your domain from spoofing.
Pro Email Deliverability Consultant Tip: Once you’ve correctly configured authentication, you can take it a step further by implementing Brand Indicators for Message Identification (BIMI). BIMI allows you to display your brand’s verified logo directly in supported inboxes, adding visual trust and increasing the likelihood that your emails are opened.
While BIMI isn’t required for deliverability yet, it enhances your brand presence and signals an extra level of legitimacy to email providers and recipients alike.
2. Run a Spam Filter Test
Not all spam filters work the same way. Gmail, Outlook & Yahoo all use different algorithms to assess your email’s legitimacy. That’s why running your message through a spam filter test is important before every campaign. These tools simulate how your email will be treated across major inbox providers and highlight any issues.
Before testing, look for red flags like excessive HTML, misleading subject lines, missing plain text versions, or poor image-to-text ratios. Even small errors, like broken links or poorly formatted tables, can trigger spam filters. A spam test gives you the feedback you need to make fixes before your email gets buried in a junk folder.
3. Test Inbox Placement
Knowing whether your email will end up in the primary tab, promotions tab, or spam folder is critical for measuring performance. You may think your campaign failed because of low open rates, but the real issue could be poor inbox placement. Using tools that test delivery across Gmail, Outlook, Apple Mail, and other platforms, you get a complete view of how your email will appear to recipients.
Using email deliverability testing for businesses also reveals geographic-specific issues, such as an email being restricted due to the sender’s location or variations between desktop and mobile clients. With that information, you can adjust your format, wording, or layout for increased visibility and engagement.
4. Clean & Segment Your List
Even a perfectly written and formatted email can perform poorly if your list hygiene is weak. Sending to outdated or disengaged contacts lowers your engagement metrics and harms your sender reputation. Internet Service Providers (ISPs) monitor bounce rates, open rates, and spam complaints to determine whether you’re a reliable sender.
Use a list-cleaning tool to remove invalid, duplicate, or spam-trap addresses. Then, segment your audience based on behavior and preferences to make your emails more relevant. A clean list boosts your overall deliverability and helps you connect with people who want to hear from you.
5. Use a Clear “From” Name & Reply Address
Trust starts with recognition. If your subscribers don’t know who the email is from, they’re more likely to ignore it or report it as spam. Always use a consistent and recognizable “from” name and email address that aligns with your brand.
Avoid using no-reply addresses, which discourage interaction and can appear suspicious to spam filters. Instead, give recipients a way to engage. You’re not just sending an email, you’re starting a conversation.
6. Write for Humans, Not Algorithms
Email content is a major factor in deliverability. While you should avoid trigger words like “FREE,” writing in a natural, conversational tone is even more important. Spam filters have evolved; they now consider engagement rates, reply frequency, and the overall value of the message.
Focus on delivering relevant, personalized content that your audience cares about. Include clear calls to action, compelling headlines, and balanced formatting. Writing for humans, not algorithms, improves both inbox placement & conversions.
7. Include a Plain Text Version
Many marketers overlook this step, but it’s crucial. Including a plain text version of your email ensures that recipients using older email clients or those with strict security settings can still read your message. Some spam filters even penalize emails that don’t have a plain text alternative.
Most Email Service Providers (ESPs) make this easy to set up. Simply create a text-only version that mirrors your main content and avoids extraneous formatting. This added layer of accessibility supports the user experience and message deliverability.
8. Avoid Sudden Spikes in Volume
Email providers track your sending behavior over time. If you go from sending 500 emails to 5,000 overnight, it raises red flags, even if you’re sending to a legitimate list. Warming up your domain gradually helps establish trust and credibility with ISPs.
If you’re planning a large campaign, ramp up volume in stages over several days or weeks. This reduces the risk of throttling, spam filtering, or delivery delays.
9. Monitor Your Sender Reputation
Your sender reputation is like a credit score for your domain; it reflects how email providers view your trustworthiness. A poor score can cause your emails to be delayed, filtered, or blocked altogether.
Use deliverability tools to track metrics that can impact your sender reputation like blacklists, bounce rates and complaint reports. If you notice a dip in reputation, pause large sends and address the issue immediately. Proactive monitoring keeps your domain healthy and your campaigns on track.
10. Confirm Your Unsubscribe Is Working
A working unsubscribe link keeps you compliant and helps protect your deliverability. Users who can’t easily opt out are more likely to mark your message as spam. That hurts your sender reputation and reduces your future reach.
Always include a visible unsubscribe option at the bottom of your email. Test it before each campaign to ensure it works properly. A respectful unsubscribe process can boost trust & retention among your engaged subscribers.
Send with Confidence
Deliverability is the foundation of your entire email marketing strategy. Use this checklist before each campaign, and your message has the best chance of reaching the right inbox. Whether you’re sending newsletters, promotions, or transactional emails, following these steps will increase your deliverability.
Your message deserves to be seen. Don’t let technical blind spots undo all your hard work. Test, fix, monitor & improve every single time with MailGenius.
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Email deliverability is crucial; even the best message won’t reach the inbox without it. To improve your chances of avoiding the spam folder, take key technical and content steps before sending your campaign. Explore this infographic for ten quick tips to boost email deliverability.
