{"id":24029,"date":"2025-10-09T14:17:45","date_gmt":"2025-10-09T14:17:45","guid":{"rendered":"https:\/\/1-grid.com\/knowledge\/mailchannels-errors-codes\/"},"modified":"2025-10-09T14:17:46","modified_gmt":"2025-10-09T14:17:46","slug":"mailchannels-errors-codes","status":"publish","type":"ht_kb","link":"https:\/\/1grid.co.za\/knowledge\/mailchannels-errors-codes\/","title":{"rendered":"MailChannels Error Codes and How to Fix Them"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"><\/blockquote>\n\n\n\n<p><a href=\"https:\/\/www.mailchannels.com\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>MailChannels<\/strong><\/a> helps ensure safe email delivery by blocking spam and enforcing sending policies. When emails fail, you may see an error code, and these may seem intimidating, but each one has a clear meaning and a fix. By understanding MailChannels error codes, what they mean and applying the right steps, such as cleaning mailing lists, enabling SPF\/DKIM\/DMARC, or avoiding spam-like content, you can resolve most issues quickly and improve your sending reputation.\u00a0\u00a0<\/p>\n\n\n\n<p>This guide will help you decipher common error codes and how to fix them.&nbsp;<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1600\" height=\"600\" src=\"https:\/\/1grid.co.za\/knowledge\/wp-content\/uploads\/2022\/02\/1-grid-Images-for-KB-Articles-1000-x-600-px-44.png\" alt=\"\" class=\"wp-image-33783\"\/><\/figure>\n<\/div>\n\n\n<div class=\"wp-block-ht-block-toc is-style-rounded htoc htoc--position-wide toc-list-style-plain\" data-htoc-state=\"expanded\"><span class=\"htoc__title\"><span class=\"ht_toc_title\">Table of Contents<\/span><span class=\"htoc__toggle\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"16\" height=\"16\"><g fill=\"#444\"><path d=\"M15 7H1c-.6 0-1 .4-1 1s.4 1 1 1h14c.6 0 1-.4 1-1s-.4-1-1-1z\"><\/path><path d=\"M15 1H1c-.6 0-1 .4-1 1s.4 1 1 1h14c.6 0 1-.4 1-1s-.4-1-1-1zM15 13H1c-.6 0-1 .4-1 1s.4 1 1 1h14c.6 0 1-.4 1-1s-.4-1-1-1z\"><\/path><\/g><\/svg><\/span><\/span><div class=\"htoc__itemswrap\"><ul class=\"ht_toc_list\"><li class=\"\"><a href=\"#htoc-\">Common MailChannels Error Codes and Fixes\u00a0\u00a0\u00a0<\/a><ul class=\"ht_toc_child_list\"><li class=\"\"><a href=\"#htoc-1\">550 5.7.1 [CS] Message Blocked \u2013 Spam\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-11\">550 5.7.1 [ESA] Sender Blocked Error\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-1111\">550 5.7.1 [RBL] Sender Blocked \u2013 Blacklist\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-111111\">550 5.7.1 [CS] Virus Detected in Message\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-11111111\">550 5.7.1 [IRR] Too Many Invalid Recipients\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-1111111111\">550 5.7.1 [HIC] Abuse Detected\u00a0<\/a><\/li><\/ul><\/li><li class=\"\"><a href=\"#htoc-1111111111111\">Preventing MailChannels Errors\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-1111111111111111\">When to Contact 1-grid Support<\/a><\/li><li class=\"\"><a href=\"#htoc-1111111111111111111\">FAQs\u00a0\u00a0<\/a><\/li><li class=\"\"><a href=\"#htoc-1111111111111111111111111\">Additional Resources\u00a0<\/a><\/li><\/ul><\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-\"><strong>Common MailChannels Error Codes and Fixes\u00a0\u00a0\u00a0<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-1\"><strong>550 5.7.1 [CS] Message Blocked \u2013 Spam\u00a0<\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-111\">Your message was detected as spam and blocked. A non-delivery report is sent with the reason.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li>Review the message for spam-like content or formatting.\u00a0<\/li>\n\n\n\n<li>If this was a <strong>false positive<\/strong>, contact 1-grid Support to log a request with MailChannels.<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-11\"><strong><strong>550 5.7.1 [ESA] Sender Blocked Error\u00a0<\/strong><\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-11111\">Abuse was detected from your account. This could include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Spam or bulk email\u00a0<\/li>\n\n\n\n<li>High complaint rates\u00a0<\/li>\n\n\n\n<li>Large numbers of invalid recipients\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li>Change your password (use at least 8 characters with a mix of upper\/lowercase, numbers, and symbols).\u00a0<\/li>\n\n\n\n<li>Update your operating system with the latest security patches.\u00a0<\/li>\n\n\n\n<li>Run a full scan with up-to-date antivirus software to check for malware.\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-1111\"><strong><strong><strong>550 5.7.1 [RBL] Sender Blocked \u2013 Blacklist\u00a0<\/strong><\/strong><\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-1111111\">Your domain or IP is listed on a global blacklist (e.g., <a href=\"https:\/\/www.spamhaus.org\/blocklists\/domain-blocklist\/\"><strong>Spamhaus<\/strong><\/a>).<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li>Check the IP or domain listed in the error against RBLs (use tools like <a href=\"https:\/\/check.spamhaus.org\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Spamhaus Domain Lookup Tool<\/strong><\/a>).\u00a0<\/li>\n\n\n\n<li>If listed, request delisting directly from the blacklist provider.\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-111111\"><strong><strong><strong><strong>550 5.7.1 [CS] Virus Detected in Message\u00a0<\/strong><\/strong><\/strong><\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-111111111\">An outgoing email from your account contains a virus.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=email+password&amp;ht-kb-search=1&amp;lang=\"><strong>Change your password<\/strong><\/a> immediately.\u00a0<\/li>\n\n\n\n<li>Update your operating system with the latest security updates.\u00a0<\/li>\n\n\n\n<li>Update antivirus software and run a full system scan.\u00a0<\/li>\n\n\n\n<li>If the problem persists, contact 1-grid Support.\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-11111111\"><strong><strong><strong><strong><strong><strong>550 5.7.1 [IRR] Too Many Invalid Recipients\u00a0<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-11111111111\">Your account sent emails to <a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-resolve-mailchannels-error-550-too-many-invalid-recipients\/\"><strong>too many invalid addresses<\/strong><\/a>, harming your sending reputation.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li>Clean your mailing list using verification tools (e.g., <a href=\"https:\/\/www.verifyemailaddress.org\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>VerifyEmailAddress.org<\/strong><\/a>, <a href=\"https:\/\/mailtester.com\/en\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>MailTester.com<\/strong><\/a>).\u00a0<\/li>\n\n\n\n<li>Follow best practices:\u00a0<\/li>\n\n\n\n<li>Use <a href=\"https:\/\/www.brevo.com\/blog\/double-opt-in\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>double opt-in<\/strong><\/a> to confirm valid addresses.\u00a0<\/li>\n\n\n\n<li>Remove invalid recipients immediately.\u00a0<\/li>\n\n\n\n<li>Send only to contacts who subscribed to your list.\u00a0<\/li>\n\n\n\n<li>Once the list is cleaned, you\u2019ll be able to send emails again automatically.\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"htoc-1111111111\"><strong><strong><strong><strong><strong><strong><strong>550 5.7.1 [HIC] Abuse Detected\u00a0<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What This Error Means<\/strong><\/summary>\n<p id=\"htoc-111111111111\">Abusive behaviour was detected from your account, often due to a compromise.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How to Fix<\/strong><\/summary>\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=email+password&amp;ht-kb-search=1&amp;lang=\"><strong>Change your password<\/strong><\/a> immediately (strong, unique format).\u00a0<\/li>\n\n\n\n<li>Ensure your operating system has the latest updates.\u00a0<\/li>\n\n\n\n<li>Update antivirus software and run a full system scan to remove any malware.\u00a0<\/li>\n<\/ul>\n<\/details>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-1111111111111\"><strong>Preventing MailChannels Errors\u00a0<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li id=\"htoc-11111111111111\">First, <strong>set up <\/strong><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-setup-an-spf-record-cpanel\/\"><strong>SPF<\/strong><\/a><strong>, DKIM, and DMARC<\/strong> to authenticate your email.\u00a0<\/li>\n\n\n\n<li id=\"htoc-next-use-clean-verified-mailing-lists-only\">Next, <strong>use clean, verified mailing lists<\/strong> only.\u00a0<\/li>\n\n\n\n<li id=\"htoc-then-monitor-bounce-rates-and-remove-invalid-addresses\">Then, <strong>monitor bounce rates and remove invalid addresses<\/strong>.\u00a0<\/li>\n\n\n\n<li id=\"htoc-in-addition-avoid-spam-like-subjects-and-heavy-attachments\">In addition, <strong>avoid spam-like subjects and heavy attachments<\/strong>.\u00a0<\/li>\n\n\n\n<li id=\"htoc-111111111111111\">Finally, <strong>limit sending volume to avoid throttling<\/strong>.\u00a0<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-1111111111111111\"><strong>When to Contact 1-grid Support<\/strong><\/h2>\n\n\n\n<p>If errors persist even after trying these solutions, reach out to 1-grid Support.&nbsp;&nbsp;<\/p>\n\n\n\n<p>Provide the following (with screenshots, where possible):&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li id=\"htoc-11111111111111111\">The full bounce-back message.\u00a0<\/li>\n\n\n\n<li id=\"htoc-steps-you-ve-already-taken\">Steps you\u2019ve already taken.\u00a0<\/li>\n\n\n\n<li id=\"htoc-111111111111111111\">A copy of your SPF\/DKIM\/DMARC records for review.\u00a0<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-1111111111111111111\"><strong>FAQs\u00a0\u00a0<\/strong><\/h2>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>Do all MailChannels errors mean my domain is blacklisted?<\/strong><\/summary>\n<p id=\"htoc-11111111111111111111\">No, many are temporary or content-related. Blacklisting is rare but possible if sending practices violate policies.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>Can MailChannels errors affect only Gmail?<\/strong><\/summary>\n<p id=\"htoc-111111111111111111111\">While Gmail is stricter, MailChannels applies policies across all providers.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>How do I avoid \u201ctoo many invalid recipients\u201d errors?<\/strong><\/summary>\n<p id=\"htoc-1111111111111111111111\">Regularly clean your mailing lists and use confirmed opt-ins.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>Will enabling DKIM and SPF fix all errors?\u00a0<\/strong><\/summary>\n<p id=\"htoc-11111111111111111111111\">No, as while they prevent many issues, practicing sending best practices also matter.<\/p>\n<\/details>\n\n\n\n<details class=\"wp-block-details is-layout-flow wp-block-details-is-layout-flow\"><summary><strong>What\u2019s the difference between a temporary and permanent error?\u00a0<\/strong><\/summary>\n<p id=\"htoc-111111111111111111111111\">Temporary errors (421, 451) resolve on retry while permanent ones (550, 554) need action before resending.<\/p>\n<\/details>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-1111111111111111111111111\"><strong>Additional Resources\u00a0<\/strong><\/h2>\n\n\n\n<p><a href=\"https:\/\/1grid.co.za\/knowledge\/blocked-via-mailchannels-due-to-spam\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Blocked via Mailchannels Due to Spam<\/strong><\/a>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-avoid-mailchannels-blocks\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Avoid MailChannels Blocks<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-resolve-mailchannels-error-550-too-many-invalid-recipients\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Resolve MailChannels Error 550 \u201cToo many invalid recipients\u201d<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/top-10-common-email-issues-and-how-to-resolve-them\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Top 10 Common Email Issues and How to Resolve Them<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/setting-up-email-in-outlook-via-windows-control-panel\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Setting Up Email in Outlook via Windows Control Panel<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-set-up-email-on-android-for-your-1grid-email-accounts\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Set Up Email on Android for Your 1-grid Email Accounts<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/settings-to-configure-your-1grid-email-accounts-across-devices\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Settings to Configure Your 1-grid Email Accounts Across Devices<\/strong><\/a><strong>\u00a0\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/resolving-email-error-messages-when-sending-to-gmail-accounts\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Resolving Email Error Messages When Sending to Gmail Accounts<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/what-is-ip-blacklisting\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>What is IP Blacklisting?<\/strong><\/a>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-check-if-my-ip-is-blacklisted\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How Do I Check if My IP is Blacklisted?<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/spamtitan-how-to-blacklist-an-email-address-or-domain\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>SpamTitan: How to Blacklist an Email Address or Domain<\/strong><\/a>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/what-is-email-spoofing\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>What Is Email Spoofing? How It Works and How to Protect Yourself\u00a0<\/strong><\/a>\u00a0\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-spot-a-scam-email\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Spot a Scam Email<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=email+headers&amp;ht-kb-search=1&amp;lang=\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Email Headers FAQs<\/strong><\/a><br><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=email&amp;ht-kb-search=1&amp;lang=\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Email FAQs<\/strong><\/a><br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-enable-dkim-and-spf-on-your-mail-domain\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Enable DKIM and SPF on Your Mail Domain<\/strong><\/a><strong>\u00a0<\/strong>\u00a0<br><a href=\"https:\/\/1grid.co.za\/knowledge\/why-ssl-the-purpose-of-using-ssl-certificates\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Why SSL? The Purpose of Using SSL Certificates<\/strong><\/a><br><a href=\"https:\/\/1grid.co.za\/knowledge\/what-is-a-domain-name-server-dns\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>What is a Domain Name Server (DNS)?<\/strong><\/a><br><a href=\"https:\/\/1grid.co.za\/knowledge\/how-to-update-your-domains-nameservers-at-1-grid\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>How to Update Your Domain\u2019s Nameservers at 1-grid<\/strong><\/a><strong>\u00a0<\/strong><br><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=mailchannels&amp;ht-kb-search=1&amp;lang=\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>MailChannels FAQs<\/strong><\/a><br><a href=\"https:\/\/1grid.co.za\/knowledge\/?s=spamtitan&amp;ht-kb-search=1&amp;lang=\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>SpamTitan FAQs<\/strong><\/a>\u00a0<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"htoc-11111111111111111111111111\"><strong>Need Additional Support?\u00a0<\/strong><\/h2>\n\n\n\n<p><strong>We&#8217;re Here to <\/strong><a href=\"https:\/\/1grid.co.za\/knowledge\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>Help<\/strong><\/a><strong>:<\/strong>&nbsp;<\/p>\n\n\n\n<p>Understanding MailChannels error codes and how to resolve them doesn\u2019t have to feel technical with this easy-to-reference guide. Stuck? Contact our Support Team for clarity and guidance (<a href=\"https:\/\/1grid.co.za\/contact-us\/\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>https:\/\/1grid.co.za\/contact-us\/<\/strong><\/a>). We&#8217;re ready to see how we can help!&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\"><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>MailChannels helps ensure safe email delivery by blocking spam and enforcing sending policies. When emails fail, you may see an error code, and these may seem intimidating, but each one has a clear meaning and a fix. By understanding MailChannels error codes, what they mean and applying the right steps,&#8230;<\/p>\n","protected":false},"author":21,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"inline_featured_image":false,"footnotes":""},"ht-kb-category":[1173,1194],"ht-kb-tag":[200,336,344,369,1495,597,598,935,1046],"class_list":["post-24029","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-email","ht_kb_category-email-troubleshooting","ht_kb_tag-code","ht_kb_tag-email","ht_kb_tag-email-hosting","ht_kb_tag-error","ht_kb_tag-error-codes","ht_kb_tag-mailchannel","ht_kb_tag-mailchannels","ht_kb_tag-spam","ht_kb_tag-troubleshooting"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.0 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>MailChannels Error Codes and How to Fix Them - 1-grid Knowledge Base<\/title>\n<meta name=\"description\" content=\"Understand MailChannels error codes and how to fix them for common issues like spam blocks, invalid recipients, and policy rejections.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/1grid.co.za\/knowledge\/mailchannels-errors-codes\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"MailChannels Error Codes and How to Fix Them - 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