{"id":4084,"date":"2025-06-06T10:38:10","date_gmt":"2025-06-06T10:38:10","guid":{"rendered":"https:\/\/www.warmy.io\/blog\/email-deliverability-testing-101-tools-metrics-what-you-should-be-looking-for\/"},"modified":"2026-04-08T11:30:50","modified_gmt":"2026-04-08T11:30:50","slug":"email-deliverability-testing-101-tools-metrics-what-you-should-be-looking-for","status":"publish","type":"post","link":"https:\/\/www.warmy.io\/blog\/email-deliverability-testing-101-tools-metrics-what-you-should-be-looking-for\/","title":{"rendered":"Email Deliverability Testing 101: Tools &amp; Metrics"},"content":{"rendered":"<p>The success of your email marketing\u2002efforts depends a great deal on your email deliverability. No matter how strong your message is, if it\u2019s not getting into the inbox,\u2002you\u2019re wasting your time. In 2025,\u2002the world has<a href=\"https:\/\/www.radicati.com\/wp\/wp-content\/uploads\/2023\/04\/Email-Statistics-Report-2023-2027-Executive-Summary.pdf\" rel=\"noopener\" target=\"_blank\" rel=\"noopener noreferrer\"> around 4.6 billion email users<\/a>. Now, when<a href=\"https:\/\/www.statista.com\/statistics\/420400\/spam-email-traffic-share-annual\/#:~:text=In+2023%2C+nearly+45.6+percent,of+e%2Dmail+traffic+worldwide.\" rel=\"noopener\" target=\"_blank\" rel=\"noopener noreferrer\"> 45.6% of global emails<\/a> end up in spam, you see why email deliverability is no easy feat.<\/p>\n<p>We\u2019ll explain what email deliverability testing is, why it matters, and the most important performance benchmarks you should be monitoring to see if your emails are doing all they can for you.<\/p>\n<p>We\u2019ll also show you the best tools and resources at your disposal to run tests\u2002and increase your email deliverability. And by the end of this guide, you\u2019ll be an expert at how to read your test results and what you can do to take action to remedy any problems so your emails end up where they\u2019re supposed to, not lost in the internet\u2019s black hole.<\/p>\n<h2><b>What is email deliverability and why does it matter?<\/b><\/h2>\n<p><b>Email deliverability:<\/b> Emails are actually reaching your recipients\u2019 inboxes rather than bouncing or being sent to the spam folder or junk folder.<\/p>\n<p>This isn\u2019t even a question of whether or not your emails were sent. It\u2019s whether or not they\u2019ve been received by the email server, and made it through the spam filters that decide whether your messages are allowed in. If your emails are consistently blocked or filtered as spam, it can damage your <a href=\"https:\/\/www.warmy.io\/blog\/the-ultimate-guide-to-understanding-and-improve-domain-reputation\/\" target=\"_blank\" rel=\"noopener noreferrer\">sender reputation<\/a> and hurt your long-term email engagement.<\/p>\n<h3>Why is email deliverability so important?<\/h3>\n<p>When you email someone, you\u2019d like that email to reach the recipient, wouldn\u2019t you? You didn\u2019t send that email into a void to sit there unread. High deliverability is crucial to\u2002the success of your marketing campaigns, as low deliverability can greatly hinder your sales outreach.<\/p>\n<p>Deliverability isn\u2019t only a technical issue. It is closely connected to the success\u2002of your campaign:<\/p>\n<ul>\n<li>Emails that land in spam never get opened, clicked or acted on. In reality,\u2002your open rates can be affected by poor deliverability, with less engagement affecting total business results.<\/li>\n<li>On the other hand, a good email deliverability strategy can increases the odds of your emails hitting the right inbox, delivering your message, getting noticed, and, ultimately, conversions.<\/li>\n<\/ul>\n<p>Without good delivery testing, you may never even know that your emails are getting marked as spam blocked. That\u2019s why testing and tracking\u2002your email campaigns is a must, if you want to hit as many targets as possible and improve performance.<\/p>\n<h2><b>Key email deliverability metrics you should track<\/b><\/h2>\n<p>To successfully monitor and\u2002optimize email deliverability, look out for a number of important metrics that help you understand how your emails are doing.<\/p>\n<h3>Inbox placement rate<\/h3>\n<p>The inbox placement rate refers to the percentage of emails that get delivered to the recipient\u2019s inbox as opposed to being sent to the spam folder or even being blocked. This is one of the most critical deliverability measures.<\/p>\n<p><b>Why it matters:<\/b><\/p>\n<ul>\n<li>A low inbox placement rate means your emails are being filtered or rejected by email providers.<\/li>\n<li>Tracking inbox placement helps you understand how well your email provider trusts your domain and emails.<\/li>\n<\/ul>\n<p><b>\ud83d\udd16 Related Reading<\/b>:<a href=\"https:\/\/www.warmy.io\/blog\/inbox-placement-test-warmy-io-s-solution-to-email-spam-challenges\/\" target=\"_blank\" rel=\"noopener noreferrer\"> Inbox Placement Test: Warmy.io\u2019s Solution to Email Spam Challenges<\/a><\/p>\n<h3>Bounce rate<\/h3>\n<p><a href=\"https:\/\/www.warmy.io\/blog\/bounced-emails-solutions-gmail-outlook-yahoo\/\" target=\"_blank\" rel=\"noopener noreferrer\">Bounce rate<\/a> refers to the percentage of emails that fail to deliver to the recipient\u2019s inbox. There are two types of bounces:<\/p>\n<ul>\n<li><b>Hard bounces<\/b>: Permanent delivery failures (e.g., invalid email addresses).<\/li>\n<li><b>Soft bounces<\/b>: Temporary issues (e.g., full inbox, server errors).<\/li>\n<\/ul>\n<p><b>Why it matters:<\/b><\/p>\n<ul>\n<li>High bounce rates can ruin your sender reputation and lead to a higher likelihood of more emails being tagged as spam or getting blocked.<\/li>\n<li>Soft bounces are a short-term issue, but frequent hard bounces may suggest a problem with your email list.<\/li>\n<\/ul>\n<p><b>\ud83d\udd16 Related Reading:<\/b><a href=\"https:\/\/www.warmy.io\/blog\/its-time-to-bounce-back-esp-specific-strategies-that-actually-work\/\" target=\"_blank\" rel=\"noopener noreferrer\"> It\u2019s Time to Bounce Back: ESP-Specific Strategies That Actually Work<\/a> is a report from the Warmy Research Team which takes a deep dive into why emails bounce across different email service providers.<\/p>\n<h3>Domain reputation<\/h3>\n<p>Your domain\u2019s reputation is a\u2002score that ESPs will use to gauge your trustworthiness based on your sending history and your engagement metrics.<\/p>\n<p><b>Why it matters:<\/b><\/p>\n<ul>\n<li>A high reputation means your emails are more likely to land in the inbox.<\/li>\n<li>A low domain reputation results in deliverability issues, as ESPs will scrutinize your emails more heavily, possibly filtering them into spam.<\/li>\n<li>Domain reputation is built over time through consistent sending practices, good list hygiene, and maintaining a positive sending history.<\/li>\n<\/ul>\n<h3>Spam complaints and engagement metrics<\/h3>\n<p><a href=\"https:\/\/www.warmy.io\/blog\/spam-complaint-rate\/\" target=\"_blank\" rel=\"noopener noreferrer\">Spam complaints<\/a> occur whens recipients report your emails as spam. A high spam score means your emails are often marked as spam and your emails are unwanted\u2014which can seriously kill your deliverability.<\/p>\n<p><b>Why it matters:<\/b><\/p>\n<ul>\n<li>It\u2019s also important to monitor engagement metrics such as open rates, click-through rates to understand how well your emails are connecting with your recipients. Low engagement is a signal that\u2002your emails may not be as relevant or useful as they need to be.<\/li>\n<\/ul>\n<p><b>\ud83d\udd16\u00a0 Relevant Reading:<\/b> <a href=\"https:\/\/www.warmy.io\/blog\/boost-your-email-click-through-rate-and-skyrocket-engagement\/\" target=\"_blank\" rel=\"noopener noreferrer\">Boost Your Email Click-Through Rate and Skyrocket Engagement<\/a><\/p>\n<h2><b>How deliverability testing tools help you<\/b><\/h2>\n<p>Email deliverability testing tools are a must-have to assure you are in the loop with how your emails are doing and troubleshooting any potential problems before they negatively impact your email campaigns. These tools let you hone your email outreach and build up your sender reputation.<\/p>\n<h3>What email deliverability testing tools do<\/h3>\n<ul>\n<li>Analyzes how your emails perform across different email service providers (ESPs), checking whether they land in the inbox, spam folder, or get blocked altogether.\u00a0<\/li>\n<li>Discover email-related problems in your setup (structure of emails, contents of those emails, and configuration, such as not adding any authentication records) which may be affecting your deliverability.<\/li>\n<li>Provide insights into your sender reputation, bounce rates, and other key metrics that impact your email success.<\/li>\n<\/ul>\n<h2><b>How does Warmy\u2019s free email deliverability test work?<\/b><\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/03\/11093324\/691shots_so.webp\" alt=\"A dashboard displaying a weekly health score of 85 with sections for CPM Metrics, Domain Records, Blacklist, and Placement test. Metrics show various scores like open rate, domain reputation, and email placement percentages for Gmail and Outlook.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<h3>Step 1: Access Warmy.io\u2019s Free Deliverability Test<\/h3>\n<p>Yes, it\u2019s free! No complicated signups, no technical setup\u2014to test your email deliverability, just head over to <a href=\"https:\/\/www.warmy.io\/free-tools\/email-deliverability-test\" target=\"_blank\" rel=\"noopener noreferrer\">Warmy\u2019s Free Email Deliverability Test.<\/a><\/p>\n<h3>Step 2: Send an email to the provided addresses<\/h3>\n<p>Open your email platform (Gmail, Outlook, or your preferred tool) and send a real email to the addresses provided by Warmy. It can be an upcoming campaign or just a test email with links, images, and formatting. This step mimics what your actual recipients would see, and that\u2019s exactly what the tool analyzes.<\/p>\n<h3>Step 3: Let Warmy work its magic<\/h3>\n<p>In about 3-5 minutes, Warmy will run its analysis and provide insights in a deliverability report:<\/p>\n<ul>\n<li>The percentage of emails that landed in the inbox, promotions tab, or spam across providers like Gmail, Outlook, and Yahoo.<\/li>\n<li>The percentage of emails that weren\u2019t delivered at all.<\/li>\n<li>Whether your domain or IP is listed on any major blacklists.<\/li>\n<\/ul>\n<h3>Step 4: Get clear, actionable results inside the Warmy dashboard<\/h3>\n<p>Warmy paid users gain access to even more detailed data from deliverability tests within the platform. And don\u2019t worry\u2014it\u2019s free for seven days during the trial. You can rerun tests and get additional insights, such as:<\/p>\n<ul>\n<li>Your email deliverability score<\/li>\n<li>The status of your DNS records<\/li>\n<li>Spam rate, domain reputation, and IP reputation scores<\/li>\n<\/ul>\n<p>Best of all, no technical expertise is required. It\u2019s built for marketers, founders, and business owners who want fast, actionable answers without diving into confusing jargon.<\/p>\n<h2><b>Taking the next step after deliverability testing<\/b><\/h2>\n<p>You now have a clear idea of your current deliverability. Beyond the free <a href=\"https:\/\/www.warmy.io\/free-tools\/email-deliverability-test\" target=\"_blank\" rel=\"noopener noreferrer\">email deliverability test<\/a>, Warmy offers a comprehensive suite of features designed to ensure your emails land in the inbox and perform at their best. Here are some of the standout features:<\/p>\n<h3>Check your authentication setup<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/03\/11093355\/848shots_so.webp\" alt=\"A website interface titled Free DMARC Record Generator with a form to enter a domain for generating a DMARC record. Below the title are navigation buttons for Domain, ESP, Email, and DMARC value. A Next button is at the bottom.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<p>Proper email authentication is essential for preventing your emails from being flagged or rejected. Just\u2002as a passport confirms your identity, email authentication confirms that you\u2019re a trustworthy sender<\/p>\n<p>If<a href=\"https:\/\/www.warmy.io\/blog\/why-do-you-need-to-configure-spf-dkim-and-dmarc\/\" target=\"_blank\" rel=\"noopener noreferrer\"> SPF, DKIM, or DMARC records<\/a> are not present or setup is incorrect, email providers will not be able to authenticate the message. They will treat it as potentially unsafe and either block the message or send it directly to the spam folder.<\/p>\n<ul>\n<li><b>Configure SPF (Sender Policy Framework):<\/b> This ensures that only authorized mail servers can send emails on behalf of your domain. Warmy\u2019s <a href=\"https:\/\/www.warmy.io\/free-tools\/spf-generator\" target=\"_blank\" rel=\"noopener noreferrer\"><b>Free SPF Record Generator<\/b><\/a> creates a valid SPF record to prevent unauthorized senders.<\/li>\n<li><b>Use DKIM (DomainKeys Identified Mail):<\/b> DKIM adds a digital signature to your emails, confirming their authenticity.<\/li>\n<li><b>Implement DMARC (Domain-based Message Authentication, Reporting &amp; Conformance):<\/b> DMARC helps manage how email providers handle emails that fail SPF or DKIM checks, ensuring that your messages aren\u2019t spoofed. Use Warmy\u2019s <a href=\"https:\/\/www.warmy.io\/free-tools\/dmarc-generator\" target=\"_blank\" rel=\"noopener noreferrer\"><b>Free DMARC Record Generator<\/b><\/a> strengthens security and prevents phishing and spoofing attacks.<\/li>\n<\/ul>\n<h3>Run your cold email content through Warmy\u2019s Template Checker<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/05\/15090244\/template-checker-1.webp\" alt=\"A user interface displays an email template focused on improving deliverability, with subject and message fields on the left and template analysis on the right, showing stats like subject length, word count, and personalization score.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<p>Even with perfect authentication, your email content can still raise red flags and negatively impact your email deliverability.<a href=\"https:\/\/www.warmy.io\/free-tools\/template-checker\" target=\"_blank\" rel=\"noopener noreferrer\"> Warmy\u2019s Template Checker<\/a> scans your email content for spam triggers that might trigger filters. It provides specific feedback on what needs to be fixed, making it easier to fine-tune your email and re-test until everything is optimized and can avoid spam filters.<\/p>\n<p><b>Bonus:<\/b> The Template Checker now has a<a href=\"https:\/\/chromewebstore.google.com\/detail\/email-template-checker-wa\/oelldnebggajjfacfajacfbkeekeakip\" rel=\"noopener\" target=\"_blank\" rel=\"noopener noreferrer\"> <b>Chrome Extension<\/b><\/a>, allowing you to analyze your emails in real-time while drafting them, ensuring they\u2019re deliverability-friendly from the start.<\/p>\n<h3>Monitor comprehensive data via the Domain Health Hub<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/03\/11093324\/691shots_so.webp\" alt=\"A dashboard displaying a weekly health score of 85 with sections for CPM Metrics, Domain Records, Blacklist, and Placement test. Metrics show various scores like open rate, domain reputation, and email placement percentages for Gmail and Outlook.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<p>Warmy\u2019s <b>Domain Health Hub<\/b> gives you a comprehensive overview of your domain\u2019s health and performance. You\u2019ll get access to:<\/p>\n<ul>\n<li>A <b>domain health score<\/b> based on authentication records, blacklist status, and inbox placement tests.<\/li>\n<li><b>Comprehensive DNS status checks<\/b> to validate your SPF, DKIM, DMARC, rDNS, MX, and A records for stronger security.<\/li>\n<li><b>Blacklist monitoring<\/b> to track if your domain is listed and provide insights for quick fixes.<\/li>\n<\/ul>\n<p>The Health Hub also tracks your spam rate trends and overall deliverability, allowing you to monitor progress on a weekly or monthly basis.<\/p>\n<h3>Implement AI-powered warmup with customizable settings<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/03\/11092911\/8shots_so-1.webp\" alt=\"Graph showing email warmup performance with a line chart which helps with email sender reputation score. The x-axis represents dates from June 1 to June 9, and the y-axis represents email volume. Two lines indicate sent (1,200) and received (1,100) emails. Background is a soft gradient.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<p>Warmy.io\u2019s<a href=\"https:\/\/www.warmy.io\/product\/warm-up-email\" target=\"_blank\" rel=\"noopener noreferrer\"> <b>AI-powered email warmup<\/b><\/a> tool gradually builds trust with email providers by mimicking natural email interactions. This feature automatically increases your sending volume over time, so mailbox providers know your emails are trusted and valuable. It also supports over 30 languages to ensure your emails reach global audiences.<\/p>\n<p>The new Warmup Preferences feature is designed to make your email warmup process even smarter by allowing senders to tailor certain preferences, such as:<\/p>\n<ul>\n<li>Warmup distribution across GSuite, Gmail, M365, Outlook, Yahoo, and even Private SMTP.<\/li>\n<li>Choosing between engagement patterns of B2B or B2C customers.<\/li>\n<\/ul>\n<h3>Maximize deliverability with advanced seed lists<\/h3>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2025\/03\/11092907\/430shots_so-1.webp\" alt=\"A beige interface displays options for selecting the number of seeds and senders with a slider and buttons. Below, a table compares features of Gmail, Outlook, and Yahoo seeds with checkmarks for various actions.\" width=\"800\" height=\"600\" title=\"\"><\/p>\n<p>Unlike traditional warm-up tools that rely on fake email interactions, Warmy.io uses<a href=\"https:\/\/www.warmy.io\/product\/seed-list\" target=\"_blank\" rel=\"noopener noreferrer\"> <b>advanced seed lists<\/b><\/a>\u2014genuine email addresses from trusted mailboxes that engage with your emails just like real recipients. This strengthens your sender reputation across multiple email providers.<\/p>\n<p>Additionally, Warmy has introduced an <b>API Endpoint for Established Seed Lists<\/b>, making it easier to manage and configure your seed list splits directly from your system. What does this mean?<\/p>\n<ul>\n<li>No more manual updates\u2014automated seed list management saves you time and reduces errors.<\/li>\n<li>Seamless integration with real-time seed list data that goes directly into your system.<\/li>\n<li>Better inbox placement\u2014properly configured seed list splits mean fewer bounces and a stronger sender reputation.<\/li>\n<\/ul>\n<h2><b>Email best practices to improve your deliverability<\/b><\/h2>\n<p>Here\u2019s a guide to fixing common problems and implementing best practices to maintain strong deliverability over time.<\/p>\n<ul>\n<li><a href=\"https:\/\/www.warmy.io\/blog\/14-tips-for-writing-an-email-subject\/\" target=\"_blank\" rel=\"noopener noreferrer\">Review your subject line<\/a> and content to avoid spammy words or formatting.<\/li>\n<li>Ensure your email list is clean and up-to-date, removing invalid or inactive addresses that cause bounces.<\/li>\n<li>Personalize your messages to improve engagement, as low engagement rates can lead to emails being flagged as spam.<\/li>\n<li>Test your emails using tools like Warmy.io to ensure there are no hidden issues like formatting errors or spam triggers.<\/li>\n<li>Remove inactive subscribers and those with high bounce rates from your list.<\/li>\n<li><a href=\"https:\/\/www.warmy.io\/blog\/tools-for-segmenting-the-customer-base\/\" target=\"_blank\" rel=\"noopener noreferrer\">Segment your list<\/a> based on engagement levels to send targeted messages to the right audience at the right time.<\/li>\n<\/ul>\n<h2><b>Take the next step towards deliverability with Warmy<\/b><\/h2>\n<p>When it comes to getting and keeping strong email deliverability, you need to do more than just hitsend on an email. You need to understand the tech behind email deliverability, adhere to the best practices, and put the right tools in\u2002place to monitor and improve your performance.<\/p>\n<p>Warmy is an email deliverability tool that offers everything you need to monitor, test, and improve your email deliverability. From our free email deliverability testing tool to advanced features like AI-powered warmup and domain health tracking, Warmy can help you get the most out of your email outreach. Download our free <a href=\"https:\/\/www.warmy.io\/wp-content\/uploads\/2025\/04\/Email-Deliverability-Trends-2025-Guide.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">email deliverability trends report<\/a>.<\/p>\n<p><b>Ready to take control of your email deliverability?<\/b><a href=\"https:\/\/www.warmy.io\/signup\" target=\"_blank\" rel=\"noopener noreferrer\"> Sign up for Warmy today<\/a> and take the first step toward better deliverability!<\/p>\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The success of your email marketing\u2002efforts depends a great deal on your email deliverability. No matter how strong your message is, if it\u2019s not getting into the inbox,\u2002you\u2019re wasting your time. In 2025,\u2002the world has around 4.6 billion email users. Now, when 45.6% of global emails end up in spam, you see why email deliverability [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":4768,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[104],"tags":[],"class_list":["post-4084","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-email-deliverability"],"acf":[],"lang":"en","translations":{"en":4084},"pll_sync_post":[],"_links":{"self":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/4084","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/comments?post=4084"}],"version-history":[{"count":1,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/4084\/revisions"}],"predecessor-version":[{"id":5889,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/4084\/revisions\/5889"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media\/4768"}],"wp:attachment":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media?parent=4084"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/categories?post=4084"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/tags?post=4084"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}