{"id":3932,"date":"2024-08-20T08:53:35","date_gmt":"2024-08-20T08:53:35","guid":{"rendered":"https:\/\/www.warmy.io\/blog\/campaign-monitor-spf-dkim-dmarc-step-by-step-guide\/"},"modified":"2026-06-12T12:44:32","modified_gmt":"2026-06-12T12:44:32","slug":"campaign-monitor-spf-dkim-dmarc-step-by-step-guide","status":"publish","type":"post","link":"https:\/\/www.warmy.io\/blog\/campaign-monitor-spf-dkim-dmarc-step-by-step-guide\/","title":{"rendered":"Implementing SPF, DKIM, and DMARC with Campaign Monitor"},"content":{"rendered":"\n<p>SPF, DKIM, and DMARC are the three DNS-based protocols that authenticate your email identity, protect your domain from spoofing, and define how receiving servers handle failures. Correctly configuring all three with Campaign Monitor is now mandatory for any bulk sender reaching Gmail, Yahoo, or Outlook recipients.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What is Email Authentication<\/h2>\n\n\n\n<p>Email authentication is a set of protocols that let receiving mail servers verify an email genuinely originates from the domain it claims. Without it, anyone can forge your From address to send phishing emails or spam that appears to come from your brand. Learn <a href=\"https:\/\/www.warmy.io\/blog\/why-do-you-need-to-configure-spf-dkim-dmarc-and-how-to-set-them\" target=\"_blank\" rel=\"noreferrer noopener\">why SPF, DKIM, and DMARC matter<\/a> for the full business case.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Phishing and Email Spoofing Issue<\/h3>\n\n\n\n<p>Email spoofing lets attackers fabricate sender addresses to impersonate trusted brands. Phishing campaigns exploit this to steal credentials, distribute malware, and deceive recipients. The consequences \u2014 data breaches, direct revenue loss, and lasting reputational damage \u2014 are severe. Traditional security controls are not sufficient to stop these threats.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How Email Authentication Protects Your Domain<\/h3>\n\n\n\n<p>Properly configured authentication gives receiving servers a structured way to verify sender legitimacy. It:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Blocks unauthorized use of your domain in the From address.<\/li>\n\n\n\n<li>Reduces the likelihood of your emails landing in spam.<\/li>\n\n\n\n<li>Protects your brand&#8217;s sender reputation.<\/li>\n\n\n\n<li>Improves deliverability to Gmail, Outlook, and Yahoo.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">How SPF, DKIM, and DMARC Work Together<\/h3>\n\n\n\n<p>Each protocol addresses a different layer of authentication, and they are most effective in combination:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SPF confirms the sending server is authorized to send email for your domain.<\/li>\n\n\n\n<li>DKIM cryptographically signs the email to confirm its content has not been altered in transit.<\/li>\n\n\n\n<li>DMARC ties SPF and DKIM together, defining how failures are handled and enabling aggregate reporting.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Why SPF, DKIM, and DMARC Are Now Mandatory (Google &amp; Yahoo 2024 Requirements)<\/h2>\n\n\n\n<p>Since February 2024, Google and Yahoo require all bulk senders \u2014 those sending 5,000 or more emails per day \u2014 to have DMARC at minimum p=none, with properly authenticated SPF and DKIM. Emails failing DMARC alignment face temporary errors and escalating rejection rates at Gmail and Yahoo, the two largest inbox providers globally. Review the full requirements at <a href=\"https:\/\/support.google.com\/mail\/answer\/81126\" target=\"_blank\" rel=\"noreferrer noopener\">Google&#8217;s Email Sender Guidelines<\/a>.<\/p>\n\n\n\n<p>Gmail tightened enforcement in November 2025, with non-compliant senders now facing permanent rejections. <a href=\"https:\/\/learn.microsoft.com\/en-us\/defender-office-365\/email-authentication-about\" target=\"_blank\" rel=\"noreferrer noopener\">Microsoft Outlook added equivalent requirements for 5,000+ daily senders starting May 5, 2025<\/a>, requiring SPF, DKIM, and a DMARC policy of at least p=none.<\/p>\n\n\n\n<p>The February 2024 requirements also mandate one-click unsubscribe (List-Unsubscribe header) in all commercial and promotional messages. If your Campaign Monitor sending domain is missing a DMARC record at any policy level, your campaigns risk silent rejection by every major inbox provider.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Start with p=none immediately \u2014 it meets Google&#8217;s and Yahoo&#8217;s minimum requirement without affecting delivery. Advance to stricter policies after reviewing your DMARC reports.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Sender Policy Framework (SPF)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What is SPF?<\/h3>\n\n\n\n<p>Sender Policy Framework (SPF) is an email authentication protocol that lets domain owners specify which mail servers are authorized to send email on their behalf, published as a DNS TXT record listing permitted IPs and hostnames. Full technical specification: <a href=\"https:\/\/datatracker.ietf.org\/doc\/html\/rfc7208\" target=\"_blank\" rel=\"noreferrer noopener\">RFC 7208<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">The Mechanisms of SPF<\/h3>\n\n\n\n<p>Key SPF mechanisms:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>include:<\/strong> delegates authority to another domain&#8217;s SPF record (e.g., include:_spf.createsend.com for Campaign Monitor).<\/li>\n\n\n\n<li><strong>ip4: \/ ip6:<\/strong> explicitly authorize specific IP addresses.<\/li>\n\n\n\n<li><strong>~all<\/strong> (soft fail): unlisted servers accepted but flagged. Use during initial setup.<\/li>\n\n\n\n<li><strong>-all<\/strong> (hard fail): unlisted servers rejected. Use only after full validation.<\/li>\n<\/ul>\n\n\n\n<p>Keep your SPF record under 10 DNS lookups. Exceeding the limit causes SPF failures. See our guide on <a href=\"https:\/\/www.warmy.io\/blog\/spf-alignment-issues-causes-fixes-best-practices-for-better-email-authentication\" target=\"_blank\" rel=\"noreferrer noopener\">SPF alignment issues<\/a> for the most common problems and fixes.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Set Up SPF with Campaign Monitor (Marigold)<\/h3>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"480\" src=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10-1024x480.png\" alt=\"Campaign Monitor\n\" class=\"wp-image-7088\" title=\"\" srcset=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10-1024x480.png 1024w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10-300x141.png 300w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10-768x360.png 768w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10-1536x720.png 1536w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/08\/Screenshot_10.png 1731w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>Note:<\/strong> Campaign Monitor was rebranded as Campaign Monitor by Marigold in early 2023. The sending infrastructure and DNS records are unchanged.<\/p>\n\n\n\n<p><strong>Critical \u2014 SPF alignment is not supported by Campaign Monitor.<\/strong> Campaign Monitor controls the Return-Path domain, making SPF alignment structurally unavailable. Adding the SPF include whitelists their IPs but your emails will not pass DMARC via SPF. Configure DKIM first \u2014 it is the only supported path to DMARC compliance.<\/p>\n\n\n\n<p>Adding the SPF include is still recommended as a general deliverability measure. Follow these steps:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Access your DNS records.<\/strong> Log in to your domain registrar or DNS host and open DNS management.<\/li>\n\n\n\n<li><strong>Add or update your SPF record.<\/strong> Create a TXT record with this value: <code>v=spf1 include:_spf.createsend.com ~all<\/code> \u2014 if an SPF record already exists, add the include to it, as each domain may have only one SPF record.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Type<\/th><th>Host<\/th><th>Value<\/th><\/tr><\/thead><tbody><tr><td>TXT<\/td><td>@<\/td><td>v=spf1 include:_spf.createsend.com ~all<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Wait for propagation<\/strong> \u2014 up to 48 hours.<\/li>\n\n\n\n<li><strong>Verify the record<\/strong> with Warmy&#8217;s free SPF Record Generator, which validates syntax and checks the lookup count.<\/li>\n<\/ol>\n\n\n\n<p>Not sure if your SPF record is configured correctly? <a href=\"https:\/\/www.warmy.io\/free-tools\/spf-generator\" target=\"_blank\" rel=\"noreferrer noopener\">Run a free SPF check now<\/a> and catch formatting errors before they hurt your deliverability.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"995\" height=\"651\" src=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/07\/SPF-generator.png\" alt=\"SPF generator\" class=\"wp-image-7030\" title=\"\" srcset=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/07\/SPF-generator.png 995w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/07\/SPF-generator-300x196.png 300w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/07\/SPF-generator-768x502.png 768w\" sizes=\"auto, (max-width: 995px) 100vw, 995px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">DomainKeys Identified Mail (DKIM)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What is DKIM?<\/h3>\n\n\n\n<p>DKIM is an email authentication method that uses public-key cryptography to sign outgoing messages, letting receiving servers confirm the email is genuine and unaltered. Full specification: <a href=\"https:\/\/datatracker.ietf.org\/doc\/html\/rfc6376\" target=\"_blank\" rel=\"noreferrer noopener\">RFC 6376<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How DKIM Works<\/h3>\n\n\n\n<p>When Campaign Monitor sends an email on your behalf, it adds a DKIM signature to the message headers using a private key. Your DNS record publishes the matching public key. Receiving servers query your DNS, retrieve the public key, and verify the signature. A valid signature confirms authenticity and content integrity.<\/p>\n\n\n\n<p>2048-bit DKIM keys are the baseline standard in 2026, not an advanced option. Campaign Monitor generates 2048-bit keys by default. For selector management and key rotation, see our guide on <a href=\"https:\/\/www.warmy.io\/blog\/dkim-selectors-step-by-step-guide-on-how-to-find-dkim-selectors\" target=\"_blank\" rel=\"noreferrer noopener\">DKIM selectors<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Set Up DKIM with Campaign Monitor (Marigold)<\/h3>\n\n\n\n<p>DKIM is the critical step for DMARC compliance with Campaign Monitor. Follow these steps:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Generate your DKIM key.<\/strong> Log in to Campaign Monitor. Click your profile image, select Account Settings, and navigate to authenticated domains. Enter the domain you want to authenticate.<\/li>\n\n\n\n<li><strong>Add the DKIM record to your DNS.<\/strong> Campaign Monitor provides the TXT record to add.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Type<\/th><th>Host<\/th><th>Value<\/th><\/tr><\/thead><tbody><tr><td>TXT<\/td><td>cm._domainkey<\/td><td>k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrLHiExVd55zd\/&#8230;<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Wait for DNS propagation<\/strong> \u2014 up to 48 hours.<\/li>\n\n\n\n<li><strong>Authenticate in Campaign Monitor.<\/strong> Return to Account Settings and click Authenticate now. A confirmation message appears once authentication succeeds.<\/li>\n\n\n\n<li><strong>Verify your setup<\/strong> with Warmy&#8217;s <a href=\"https:\/\/www.warmy.io\/free-tools\/email-deliverability-test\" target=\"_blank\" rel=\"noreferrer noopener\">Email Deliverability Test<\/a>, which checks DKIM configuration alongside inbox placement and blacklist status.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"Email Deliverability Test Dashboard | Onboarding\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/iU5zczpixAk?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Domain-based Message Authentication, Reporting, and Conformance (DMARC)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What is DMARC?<\/h3>\n\n\n\n<p>DMARC is a policy framework that builds on SPF and DKIM. It lets domain owners define how receiving servers handle authentication failures and receive aggregate reports. Full specification: <a href=\"https:\/\/datatracker.ietf.org\/doc\/html\/rfc7489\" target=\"_blank\" rel=\"noreferrer noopener\">RFC 7489<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How DMARC Works<\/h3>\n\n\n\n<p>DMARC checks whether an incoming email passes SPF or DKIM and whether either method is aligned with the From domain. For Campaign Monitor, DKIM alignment is the only viable path. Based on your policy, receiving servers deliver (p=none), quarantine (p=quarantine), or reject (p=reject) emails that fail authentication.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Implement DMARC with Campaign Monitor: Step-by-Step<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Create your DMARC record.<\/strong> Start with p=none \u2014 this meets Google&#8217;s and Yahoo&#8217;s minimum requirement without affecting delivery: <code>v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com<\/code><\/li>\n\n\n\n<li><strong>Add the record to DNS:<\/strong><\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Type<\/th><th>Host<\/th><th>Value<\/th><\/tr><\/thead><tbody><tr><td>TXT<\/td><td>_dmarc<\/td><td>v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Monitor your reports.<\/strong> Aggregate reports arrive at your rua address as XML, showing which servers are sending from your domain and whether they pass SPF and DKIM.<\/li>\n<\/ol>\n\n\n\n<p>Use Warmy&#8217;s <a href=\"https:\/\/www.warmy.io\/free-tools\/dmarc-generator\" target=\"_blank\" rel=\"noreferrer noopener\">free DMARC Generator<\/a> to create accurate records and select the right policy settings without manual syntax work.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"727\" src=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/06\/DMARK-generator-1024x727.png\" alt=\"DMARK generator\" class=\"wp-image-6950\" title=\"\" srcset=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/06\/DMARK-generator-1024x727.png 1024w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/06\/DMARK-generator-300x213.png 300w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/06\/DMARK-generator-768x545.png 768w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/06\/DMARK-generator.png 1172w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">DMARC Policy Progression: p=none to p=quarantine to p=reject<\/h3>\n\n\n\n<p>Google&#8217;s guidance and industry best practice both call for a phased approach. Jumping to p=reject before validating risks blocking legitimate email.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>p=none:<\/strong> Monitor only \u2014 failing emails are delivered but you receive reports. Stay here until all legitimate senders pass.<\/li>\n\n\n\n<li><strong>p=quarantine:<\/strong> Failing emails go to spam. Move here after reports confirm authorized senders are passing.<\/li>\n\n\n\n<li><strong>p=reject:<\/strong> Failing emails are rejected at the server. Move here only when fully validated.<\/li>\n<\/ul>\n\n\n\n<p>Use <code>pct=<\/code> to apply your policy to a percentage of traffic during rollout (e.g., pct=10), reducing risk as you validate.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">SPF vs DKIM vs DMARC: Quick Comparison<\/h2>\n\n\n\n<p>Here is a side-by-side breakdown of the three protocols, including their specific behavior with Campaign Monitor:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>Feature<\/th><th>SPF<\/th><th>DKIM<\/th><th>DMARC<\/th><\/tr><\/thead><tbody><tr><td><strong>What it does<\/strong><\/td><td>Verifies sending server is authorized<\/td><td>Digitally signs email content<\/td><td>Policy for auth failures + reporting<\/td><\/tr><tr><td><strong>Works via<\/strong><\/td><td>DNS TXT record listing IPs<\/td><td>Cryptographic signature in header<\/td><td>DNS TXT record referencing SPF\/DKIM<\/td><\/tr><tr><td><strong>Campaign Monitor alignment<\/strong><\/td><td>Not supported<\/td><td>Fully supported \u2014 required path<\/td><td>Passes via DKIM only<\/td><\/tr><tr><td><strong>Mandatory since?<\/strong><\/td><td>Recommended, not sufficient alone<\/td><td>Feb 2024 (Google\/Yahoo)<\/td><td>Feb 2024 \u2014 p=none minimum<\/td><\/tr><tr><td><strong>Protects against<\/strong><\/td><td>IP spoofing<\/td><td>Content tampering, spoofing<\/td><td>Phishing, unauthorized sending<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Advanced Methods to Configure SPF, DKIM, and DMARC<\/h2>\n\n\n\n<p>Beyond basic setup, these configurations further strengthen your authentication and deliverability.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Advanced SPF Configuration<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use ip4: and ip6: to authorize exact IP addresses for custom sending infrastructure.<\/li>\n\n\n\n<li>Implement SPF flattening to resolve nested includes into direct IP ranges, staying within the 10-lookup limit.<\/li>\n\n\n\n<li>Use the a: mechanism to include all IPs associated with a specific domain.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Advanced DKIM Configuration<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Implement key rotation \u2014 update DKIM keys periodically to limit exposure if a key is ever compromised.<\/li>\n\n\n\n<li>Use multiple DKIM selectors to sign different email streams independently.<\/li>\n\n\n\n<li>2048-bit keys are the current baseline. Use them for all new DKIM configurations.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Advanced DMARC Configuration<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>sp=<\/strong> sets a separate policy for subdomains \u2014 protect them at p=reject while the parent stays at p=none.<\/li>\n\n\n\n<li><strong>pct=<\/strong> applies your policy to only a defined percentage of traffic during gradual rollout.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How to Fix Common SPF, DKIM, and DMARC Issues<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">How to Fix SPF Record Syntax Errors<\/h3>\n\n\n\n<p>The most common SPF syntax errors are a missing v=spf1 version string, exceeding the 10 DNS lookup limit, and incorrect use of qualifiers. Run your record through Warmy&#8217;s SPF Generator to catch and fix these automatically.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Fix DKIM Key Mismatches<\/h3>\n\n\n\n<p>DKIM failures usually result from an incorrectly copied public key, a mismatched selector, or an expired key. Verify that your DNS record exactly matches what Campaign Monitor provided. If problems persist, generate new DKIM keys in Campaign Monitor and update the DNS record.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Resolve DMARC Policy Conflicts<\/h3>\n\n\n\n<p>DMARC problems typically arise from policies set too strictly before all senders are authenticated. Start at p=none, review your reports, and ensure every source passes DKIM before tightening your policy.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How to Fix SPF Alignment Failures with Campaign Monitor<\/h3>\n\n\n\n<p>SPF alignment failures for Campaign Monitor traffic are expected \u2014 Campaign Monitor controls the Return-Path domain and does not support custom Return-Path configuration for standard accounts. The correct fix is to ensure DKIM alignment is configured and passing. DMARC requires only one aligned method, so a DKIM pass provides full compliance.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Using Email Warmup to Improve Email Deliverability<\/h2>\n\n\n\n<p>Authentication answers the question: are you who you say you are? But inbox providers ask a second question: are you a sender we trust? That is the gap Warmy closes.<\/p>\n\n\n\n<p>Warmy is an AI-driven email warmup and deliverability platform that automatically builds your <a href=\"https:\/\/www.warmy.io\/blog\/email-sender-reputation-score\" target=\"_blank\" rel=\"noreferrer noopener\">sender reputation score<\/a>, improves inbox placement, and keeps your emails out of spam. Warmy&#8217;s warmup uses a network of 1M+ real mailboxes to generate genuine engagement signals \u2014 opens, replies, and spam recoveries \u2014 across 30+ languages, with Adeline AI building a personalized warmup schedule for each mailbox.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"965\" height=\"641\" src=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/05\/Adeline-AI.png\" alt=\"Adeline AI\" class=\"wp-image-6920\" title=\"\" srcset=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/05\/Adeline-AI.png 965w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/05\/Adeline-AI-300x199.png 300w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2024\/05\/Adeline-AI-768x510.png 768w\" sizes=\"auto, (max-width: 965px) 100vw, 965px\" \/><\/figure>\n\n\n\n<p>For Campaign Monitor users, this matters because even perfectly authenticated domains can land in spam when the sending domain is new or has low engagement history. Authentication sets the foundation. Warmup builds the reputation on top.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Warmy is an AI-driven email warmup platform that automatically builds sender reputation alongside your authentication setup. Authentication proves your identity \u2014 warmup earns your inbox placement.<\/p>\n<\/blockquote>\n\n\n\n<p>Warmy also provides free diagnostic tools to verify your setup is working: the Email Deliverability Test checks inbox placement, blacklist status, and SPF\/DKIM\/DMARC configuration; the <a href=\"https:\/\/www.warmy.io\/free-tools\/template-checker\" target=\"_blank\" rel=\"noreferrer noopener\">Email Template Checker<\/a> scans email content for spam triggers before you send, and is also available as a Chrome Extension.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker-1024x768.webp\" alt=\"Template Checker tool inside Warmy.io\" class=\"wp-image-5217\" title=\"\" srcset=\"https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker-1024x768.webp 1024w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker-300x225.webp 300w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker-768x576.webp 768w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker-1536x1152.webp 1536w, https:\/\/www.warmy.io\/blog\/wp-content\/uploads\/2026\/03\/Template-Checker.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p>Configuring SPF, DKIM, and DMARC with Campaign Monitor is no longer optional. Google, Yahoo, and Outlook have made authentication mandatory for bulk senders, and the consequences of non-compliance \u2014 campaign rejections, spam placement, and deliverability collapse \u2014 directly threaten email marketing revenue.<\/p>\n\n\n\n<p>The key steps: add Campaign Monitor&#8217;s SPF include (_spf.createsend.com) for general deliverability, configure DKIM through Account Settings (the only path to DMARC alignment), publish a DMARC record starting at p=none, monitor your reports, and advance to p=quarantine then p=reject as your setup stabilizes.<\/p>\n\n\n\n<p>Read our full <a href=\"https:\/\/www.warmy.io\/blog\/mastering-email-deliverability-the-modern-guide-to-authentication-and-inbox-warm-up\" target=\"_blank\" rel=\"noreferrer noopener\">email deliverability guide<\/a> for a comprehensive look at the relationship between authentication, reputation, and inbox placement.<\/p>\n\n\n\n<p>Protect your email deliverability and sender reputation with Warmy. <a href=\"https:\/\/www.warmy.io\/book-a-demo\" target=\"_blank\" rel=\"noreferrer noopener\">Book a free demo<\/a> and see how Warmy builds your authentication and warmup strategy from the ground up.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"How to Set Up SPF, DKIM, and DMARC for Gmail in 2026 (google workspace)\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/bXxcDJa84uA?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>SPF, DKIM, and DMARC are the three DNS-based protocols that authenticate your email identity, protect your domain from spoofing, and define how receiving servers handle failures. Correctly configuring all three with Campaign Monitor is now mandatory for any bulk sender reaching Gmail, Yahoo, or Outlook recipients. What is Email Authentication Email authentication is a set [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":7086,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[104],"tags":[],"class_list":["post-3932","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-email-deliverability"],"acf":[],"lang":"en","translations":{"en":3932},"pll_sync_post":[],"_links":{"self":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3932","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=3932"}],"version-history":[{"count":2,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3932\/revisions"}],"predecessor-version":[{"id":7090,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3932\/revisions\/7090"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media\/7086"}],"wp:attachment":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media?parent=3932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/categories?post=3932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/tags?post=3932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}