{"id":6394,"date":"2026-10-12T13:02:29","date_gmt":"2026-10-12T11:02:29","guid":{"rendered":"https:\/\/eu.klytic.com\/guides\/email-security\/"},"modified":"2026-10-12T13:32:49","modified_gmt":"2026-10-12T11:32:49","slug":"email-security","status":"publish","type":"page","link":"https:\/\/eu.klytic.com\/en\/guides\/email-security\/","title":{"rendered":"Email security"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"6394\" class=\"elementor elementor-6394 elementor-6264\" data-elementor-post-type=\"page\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b40dcdb e-con-full kly-g e-flex e-con e-parent\" data-id=\"b40dcdb\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-568c9f4 e-con-full kly-g-hero e-flex e-con e-parent\" data-id=\"568c9f4\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-90a9e3c e-con-full kly-g-hero-in e-flex e-con e-parent\" data-id=\"90a9e3c\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-9620537 elementor-widget elementor-widget-text-editor\" data-id=\"9620537\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p class=\"kly-g-crumb\"><a href=\"\/en\/\">Home<\/a><span>\u203a<\/span><a href=\"\/en\/guides\/\">Guides<\/a><\/p><p class=\"kly-g-pill\" style=\"--pill:#f87171\">Email security<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-63e75ff elementor-widget elementor-widget-heading\" data-id=\"63e75ff\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"heading.default\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">Email security<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b800651 elementor-widget elementor-widget-text-editor\" data-id=\"b800651\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p class=\"kly-g-lead\">Email security does not depend on the email system you use. <a href='\/en\/klytic-mta\/'>Klytic MTA<\/a> sits in front of your current mail server, whether it is Microsoft 365, Google Workspace, Exchange, Klytic Mail or another server, and analyzes every message before it reaches the mailbox. This section brings together the guides for understanding threats and architecture choices, then the how-tos for using Klytic MTA day to day.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c6ed040 elementor-widget elementor-widget-text-editor\" data-id=\"c6ed040\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<p class=\"kly-g-meta\"><span>Updated <b>October 2026<\/b><\/span><span><b>4 min<\/b><\/span><span>Understand and use<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-05ccbf5 e-con-full kly-g-body e-flex e-con e-parent\" data-id=\"05ccbf5\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t<div class=\"elementor-element elementor-element-b0bcadd e-con-full kly-g-article e-flex e-con e-parent\" data-id=\"b0bcadd\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-12eac07 elementor-widget elementor-widget-text-editor\" data-id=\"12eac07\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>The mailbox and the gateway are two separate purchases<\/h2><p>An email system stores mail, calendars and contacts. A security gateway decides what is allowed in. The two are chosen separately.<\/p><p>You can keep Microsoft 365, Google Workspace, Exchange or another server and change just one thing: your domain\u2019s MX record, which tells other servers where to deliver your mail. It then points to Klytic MTA, which analyzes each message, then delivers it to your email system, quarantines it or rejects it. Your users keep their tools.<\/p><p>Klytic Mail is one case among others, not a prerequisite. The mailbox itself is covered in the <a href='\/en\/guides\/business-email\/'>Email<\/a> section.<\/p><p>Klytic MTA comes in two plans. Essential covers sender authentication, anti-spam, antivirus, phishing, lookalike domains, malicious attachments, encrypted quarantine, AI arbitration of ambiguous messages and outbound mail. Advanced adds executive and financial fraud, time-of-click link rescanning, the DMARC console and logs exportable to a SIEM. Full details are on the <a href='\/en\/klytic-mta\/'>Klytic MTA<\/a> page.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d132028 elementor-widget elementor-widget-text-editor\" data-id=\"d132028\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Where the gateway can run<\/h2><p>Klytic MTA can be deployed in three ways:<\/p><ul><li><strong>in the Klytic cloud<\/strong>, on a shared, isolated platform;<\/li><li><strong>on a dedicated instance<\/strong>, reserved for your organization;<\/li><li><strong>on your premises<\/strong>, on your own servers.<\/li><\/ul><p>Hosting is possible in any geographic zone matching the applicable jurisdiction, subject to service availability, notably in Europe or Mauritius, or on the customer\u2019s servers.<\/p><p>Other architectures can be built from these three modes: cloud filtering combined with a local relay, or several interconnected regions for an organization operating in several countries. These are technical setups to be studied with Klytic, not additional offerings.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-630fcc4 elementor-widget elementor-widget-text-editor\" data-id=\"630fcc4\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Understand<\/h2><p>Guides to help you decide, useful even if you do not choose Klytic.<\/p><ul><li><a href='\/en\/email-security-gateway\/'>Built-in filter or security gateway in front of your email<\/a>: where the filter sits, and why mail should be analyzed before it enters the mailbox.<\/li><li><a href='\/en\/protect-existing-email\/'>Protect the email system you already have<\/a>: keep Microsoft 365, Google Workspace or another server, and change only the MX.<\/li><li><a href='\/en\/spam-phishing-malware-compromised-account\/'>Spam, phishing, malware and compromised accounts<\/a>: four different problems that do not call for the same response.<\/li><li><a href='\/en\/ceo-fraud-impersonation\/'>Impersonation and CEO fraud<\/a>: the fake executive, the fake supplier and the bank details change, and what technology cannot decide for you.<\/li><li><a href='\/en\/spf-dkim-dmarc-en\/'>SPF, DKIM and DMARC: what they protect, and what they do not<\/a>: what domain authentication stops, and what it lets through.<\/li><li><a href='\/en\/email-attachments-links-ransomware\/'>Attachments, links and ransomware received by email<\/a>: what the gateway examines, and the actions that remain human.<\/li><li><a href='\/en\/ai-email-filtering-privacy\/'>AI in email filtering, and what leaves the company<\/a>: when AI helps, and what it actually receives from the message.<\/li><li><a href='\/en\/email-security-logs\/'>Keeping and reviewing email security logs<\/a>: what a log contains, how long it is kept, and who can read it.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7a7ff86 elementor-widget elementor-widget-text-editor\" data-id=\"7a7ff86\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Use Klytic MTA<\/h2><p>How-tos for the gateway administrator and for the user who receives a quarantine link, whatever their email system.<\/p><ul><li><a href='\/en\/quarantine-false-positives\/'>Quarantine, false positives and reports<\/a>: release a held message, correct a false positive, report a malicious message.<\/li><li><a href='\/en\/audit-filter-decisions\/'>Read and export a filter decision<\/a>: read the score and reason in the headers, and export the logs.<\/li><li><a href='\/en\/email-filter-policies\/'>Who configures the filter in Klytic MTA<\/a>: the five tiers of rules, and who configures each one.<\/li><li><a href='\/en\/outgoing-mail-signing-recall\/'>DKIM signing, S\/MIME signing and recalling outgoing mail<\/a>: DKIM signing, delay before sending, and S\/MIME signing with your key if your email system does not support it.<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-678e638 elementor-widget elementor-widget-text-editor\" data-id=\"678e638\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Sovereignty and choice of email system<\/h2><p>A gateway sees all of your mail pass through it. The question of who operates it and which law applies to that operator therefore arises just as it does for the email system. It is covered in <a href='\/en\/what-is-sovereign-cloud\/'>What is a sovereign cloud?<\/a> and in the Digital sovereignty section. If you are also considering changing email systems, see <a href='\/en\/european-business-email\/'>choosing a European business email service<\/a> and <a href='\/en\/migrate-email-without-downtime\/'>migrating email without interruption<\/a>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-8ea2f11 e-con-full kly-g-aside e-flex e-con e-parent\" data-id=\"8ea2f11\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-66670e5 elementor-widget elementor-widget-html\" data-id=\"66670e5\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"html.default\">\n\t\t\t\t\t<nav class=\"kly-g-toc\" aria-label=\"On this page\"><p>On this page<\/p><ol><\/ol><\/nav>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-31027be elementor-widget elementor-widget-text-editor\" data-id=\"31027be\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<div class=\"kly-g-cta\"><h3>Protect your current email system<\/h3><p>Free 30-day trial, without changing email systems: Klytic prepares the configuration, then your domain\u2019s MX is updated.<\/p><p><a class=\"kly-g-btn\" href=\"\/en\/30-day-free-trial\/\">Request a trial \u2192<\/a><\/p><p style=\"margin:0\"><a class=\"kly-g-btn ghost\" href=\"\/en\/klytic-mta\/\">Discover Klytic MTA<\/a><\/p><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-9888b1b e-con-full kly-g-related e-flex e-con e-parent\" data-id=\"9888b1b\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;ekit_has_onepagescroll_dot&quot;:&quot;yes&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-214137b elementor-widget elementor-widget-text-editor\" data-id=\"214137b\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;ekit_we_effect_on&quot;:&quot;none&quot;}\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Further reading<\/h2><div class=\"kly-g-grid\"><a class=\"kly-g-card\" href=\"\/en\/email-security-gateway\/\" style=\"--cat:#dc2626\"><span class=\"c\">Understand \u00b7 Email security<\/span><span class=\"t\">Built-in filter or security gateway in front of your email<\/span><span class=\"q\">An email system\u2019s filter protects that email system. A gateway receives the domain\u2019s mail, analyzes it, then delivers it: where to place it, what it keeps.<\/span><span class=\"m\"><span>7 min read<\/span><b>Read \u2192<\/b><\/span><\/a><a class=\"kly-g-card\" href=\"\/en\/protect-existing-email\/\" style=\"--cat:#dc2626\"><span class=\"c\">Understand \u00b7 Email security<\/span><span class=\"t\">Protecting the email system you already have<\/span><span class=\"q\">Microsoft 365, Google Workspace, Exchange: you can add a security gateway without changing email services. What changes, who sets it up, the limits.<\/span><span class=\"m\"><span>7 min read<\/span><b>Read \u2192<\/b><\/span><\/a><a class=\"kly-g-card\" href=\"\/en\/quarantine-false-positives\/\" style=\"--cat:#dc2626\"><span class=\"c\">Use \u00b7 Email security<\/span><span class=\"t\">Quarantine, false positives and reporting<\/span><span class=\"q\">What happens to a message held by Klytic MTA, how to release it, correct a false positive and report a malicious message.<\/span><span class=\"m\"><span>6 min read<\/span><b>Read \u2192<\/b><\/span><\/a><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-539316dd e-con e-atomic-element e-div-block-base e-default-div e-c9fd865-4a50 \" data-id=\"539316dd\" data-element_type=\"e-div-block\" data-e-type=\"e-div-block\" data-interaction-id=\"539316dd\" data-e-type=\"e-div-block\" data-id=\"539316dd\">\n    <div class=\"elementor-element elementor-element-4f79afcb e-con e-atomic-element e-div-block-base e-default-div e-4fa9fe-ce86 \" data-id=\"4f79afcb\" data-element_type=\"e-div-block\" data-e-type=\"e-div-block\" data-interaction-id=\"4f79afcb\" data-e-type=\"e-div-block\" data-id=\"4f79afcb\">\n    \t\t\t<p class=\"e-4dcf5c70-2ec7 e-paragraph-base e-default-p\" data-interaction-id=\"330a7a35\" data-e-type=\"widget\" data-id=\"330a7a35\">Welcome offer<\/p>\n\t\t\t\t\t<h2 data-interaction-id=\"56f1f7d5\" class=\"e-347faa43-4e20 e-heading-base e-default-h2\" data-e-type=\"widget\" data-id=\"56f1f7d5\">30-day free trial, assisted migration<\/h2>\n\t\t\t\t\t<p class=\"e-7f6310da-1caa e-paragraph-base e-default-p\" data-interaction-id=\"2ce27288\" data-e-type=\"widget\" data-id=\"2ce27288\">No-commitment trial offer. An advisor will call you back to understand your needs and prepare your Klytic space.<\/p>\n\t\t<div class=\"elementor-element elementor-element-35ea29a1 e-con e-atomic-element e-div-block-base e-default-div e-1cd48b22-e6da \" data-id=\"35ea29a1\" data-element_type=\"e-div-block\" data-e-type=\"e-div-block\" data-interaction-id=\"35ea29a1\" data-e-type=\"e-div-block\" data-id=\"35ea29a1\">\n    \t\t\t<a href=\"https:\/\/eu.klytic.com\/en\/30-day-free-trial\/\" target=\"_self\" class=\"e-4a7886e3-652d e-button-base e-default-a\" data-interaction-id=\"19bfa8f1\" data-e-type=\"widget\" data-id=\"19bfa8f1\">\n\t\ud83d\ude80 Start free trial\n<\/a>\n\t\t\t\t\t<a href=\"https:\/\/eu.klytic.com\/en\/pricing\/\" target=\"_self\" class=\"e-137e863d-dd0d e-button-base e-default-a\" data-interaction-id=\"326d82ab\" data-e-type=\"widget\" data-id=\"326d82ab\">\n\tSee pricing\n<\/a>\n\t\t\n<\/div>\n\n<\/div>\n\n<\/div>\n\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":3303,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"_seopress_titles_title":"Email security: Klytic MTA guides and how-tos | Klytic","_seopress_titles_desc":"Guides to understand spam, phishing, CEO fraud, DMARC and logs, and how-tos for using Klytic MTA in front of any email system.","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"Email security: Klytic MTA guides and how-tos | Klytic","_seopress_social_fb_desc":"Guides to understand spam, phishing, CEO fraud, DMARC and logs, and how-tos for using Klytic MTA in front of any email system.","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"Email security: Klytic MTA guides and how-tos | Klytic","_seopress_social_twitter_desc":"Guides to understand spam, phishing, CEO fraud, DMARC and logs, and how-tos for using Klytic MTA in front of any email system.","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"class_list":["post-6394","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/pages\/6394","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/comments?post=6394"}],"version-history":[{"count":0,"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/pages\/6394\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/pages\/3303"}],"wp:attachment":[{"href":"https:\/\/eu.klytic.com\/en\/wp-json\/wp\/v2\/media?parent=6394"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}