{"id":5753,"date":"2022-01-24T07:56:23","date_gmt":"2022-01-24T13:56:23","guid":{"rendered":"https:\/\/www.knownhost.com\/kb\/?p=5753"},"modified":"2022-08-23T09:35:20","modified_gmt":"2022-08-23T14:35:20","slug":"smtp-error-500","status":"publish","type":"post","link":"https:\/\/www.knownhost.com\/kb\/smtp-error-500\/","title":{"rendered":"SMTP Error 500"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 ez-toc-wrap-right counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #212121;color:#212121\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #212121;color:#212121\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.knownhost.com\/kb\/smtp-error-500\/#what_does_this_mean\" >What does this mean?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.knownhost.com\/kb\/smtp-error-500\/#how_to_fix_smtp_error_500\" >How to fix SMTP Error 500?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.knownhost.com\/kb\/smtp-error-500\/#smtp_error_500_examples\" >SMTP Error 500 Examples<\/a><\/li><\/ul><\/nav><\/div>\n\n<p><strong>Description<\/strong>: Syntax error, command unrecognized (This may include errors such as command line too long).<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"what_does_this_mean\"><\/span>What does this mean?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The receiving SMTP mail server was unable to correct process the command(s) received. Also note, commands that are processed but not used will be handled with different response numbers.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"how_to_fix_smtp_error_500\"><\/span>How to fix SMTP Error 500?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>The unrecognized command response is typically in regards to antivirus or firewall software. To confirm if this is the case, temporarily disable each one, re-instating them if not the area of concern.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"smtp_error_500_examples\"><\/span>SMTP Error 500 Examples<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>SMTP Permanent Error: 500 Access Denied By Port Access<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>SMTP Error 500 Line too long<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Description: Syntax error, command unrecognized (This may include errors such as command line too long). What does this mean? The receiving SMTP mail server was unable to correct process the command(s) received. Also note, commands that are processed but not used will be handled with different response numbers. How to fix SMTP Error 500? The [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[97],"tags":[567,380,291],"class_list":["post-5753","post","type-post","status-publish","format-standard","hentry","category-other","tag-567","tag-error","tag-smtp"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>SMTP Error 500 - KnownHost<\/title>\n<meta name=\"description\" content=\"KnownHost self-hosted email guide to help you troubleshoot and fix SMTP Error 500 on your premium KnownHost server.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.knownhost.com\/kb\/smtp-error-500\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"SMTP Error 500 - 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