{"id":8516,"date":"2014-11-17T17:36:43","date_gmt":"2014-11-17T17:36:43","guid":{"rendered":"https:\/\/wp.okra.host\/article\/improving-mail-filter-performance\/"},"modified":"2021-03-07T14:24:57","modified_gmt":"2021-03-07T13:24:57","slug":"improving-mail-filter-performance","status":"publish","type":"ht_kb","link":"https:\/\/kb.okra.host\/de\/article\/improving-mail-filter-performance\/","title":{"rendered":"Improving mail filter performance"},"content":{"rendered":"<h2 id=\"overview\" >\u00dcbersicht<\/h2>\n<p>E-mail that flows into the server goes through several phases of filtering before final delivery, including:<\/p>\n<ul>\n<li><a href=\"http:\/\/www.dnsbl.info\/\">DNSBL lookups<\/a> on handshake<\/li>\n<li><a href=\"http:\/\/www.postfix.org\/POSTSCREEN_README.html\">Deep protocol<\/a> inspection<\/li>\n<li><a href=\"http:\/\/en.wikipedia.org\/wiki\/DomainKeys\">DomainKeys<\/a>\/<a href=\"http:\/\/www.openspf.org\">SPF<\/a> validation<\/li>\n<li><a href=\"http:\/\/spamassassin.apache.org\">SpamAssassin<\/a> filtering\n<ul>\n<li>Whitelist management<\/li>\n<li>Hash-sharing systems (<a href=\"http:\/\/www.rhyolite.com\/dcc\/\">DCC<\/a> &amp; <a href=\"http:\/\/razor.sourceforge.net\/\">Razor<\/a>)<\/li>\n<li>Token-based regex\u00a0matching<\/li>\n<li>Markup filtering<\/li>\n<li><strong><a href=\"http:\/\/en.wikipedia.org\/wiki\/Bayes&#039;_theorem\">Bayesian<\/a> filtering<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>All steps in\u00a0the filtering process are automated, except for <strong>Bayesian filtering<\/strong> that works by both\u00a0automatic learning and manual learning. This covers how\u00a0to train your filter to\u00a0improve\u00a0filter performance.<\/p>\n<h2 id=\"how-it-works\" >How it works<\/h2>\n<p>Bayesian filtering breaks an e-mail down into individual words, then compares the probability of words in legitimate e-mail and spam. If certain words or phrases such as &#8220;Dr. Oz&#8221;, &#8220;Solar Panels&#8221;, and &#8220;Viagra&#8221; appear more frequently in e-mail identified as spam, then that e-mail that contains such phrases is likely to be spam as well. Likewise phrases that contain, &#8220;Monday&#8221;, &#8220;Synergism&#8221;, and &#8220;Ocelot&#8221; may be less likely to contain spam based on training data. E-mails that come in with those words are rated more favorably as non-spam and, therefore, less likely to be delivered to your <a title=\"Accessing Spam folder\" href=\"https:\/\/kb.okra.host\/de\/e-mail\/accessing-spam-folder\/\">Spam folder<\/a>.<\/p>\n<h2 id=\"how-to-use-it\" >How\u00a0to use it<\/h2>\n<p>&nbsp;<\/p>\n<h3 id=\"training-by-imap-folder\" >Training by IMAP folder<\/h3>\n<p>For e-mail accounts setup as <a href=\"https:\/\/kb.okra.host\/de\/e-mail\/pop3-vs-imap-e-mail-protocols\/\">IMAP<\/a>, there is an easier process to feed data to the filter. Create an IMAP folder called &#8220;AutoSpam&#8221; (capitalization matters). Drag and drop e-mail that slips through to this folder for automatic analysis. E-mail is analyzed nightly. Once trained, these messages are discarded from your inbox.<\/p>\n<h3 id=\"creating-autospam-within-the-control-panel\" >Creating AutoSpam\u00a0within the control panel<\/h3>\n<p>An AutoSpam folder may be easily created within the control panel under <strong>Mail<\/strong> &gt; <strong>SpamAssassin Config<\/strong>. Click\u00a0<strong>Enable Folder<\/strong> unter <span style=\"text-decoration: underline\">Feedback Participation<\/span>. You will need to logout of your existing IMAP program to activate changes.<\/p>\n<div id=\"attachment_999\" style=\"width: 488px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/kb.okra.host\/wp-content\/uploads\/2014\/11\/autospam-learning-folder.gif\" rel=\"lightbox-0\" data-lbwps-width=\"478\" data-lbwps-height=\"269\" data-lbwps-srcsmall=\"https:\/\/kb.okra.host\/wp-content\/uploads\/2014\/11\/autospam-learning-folder.gif\"><img decoding=\"async\" aria-describedby=\"caption-attachment-999\" loading=\"lazy\" class=\"size-full wp-image-999\" src=\"https:\/\/kb.okra.host\/wp-content\/uploads\/2014\/11\/autospam-learning-folder.gif\" alt=\"Drag and drop learning with the AutoSpam folder\" width=\"478\" height=\"269\" \/><\/a><\/p>\n<p id=\"caption-attachment-999\" class=\"wp-caption-text\">Drag and drop learning with the AutoSpam folder<\/p>\n<\/div>\n<h3 id=\"fine-print\" >Fine print<\/h3>\n<p>Also there are a few\u00a0guidelines to bear in mind when using this service:<\/p>\n<ul>\n<li>Don&#8217;t feed the spam filter e-mails that you have received as part of a mailing list that you signed-up for\n<ul>\n<li><em>Always use the unsubscribe feature<\/em><\/li>\n<\/ul>\n<\/li>\n<li>Poisoning the filter (feeding non-spam to it) is bad. Don&#8217;t do it.<\/li>\n<li>Results are never instantaneous and take up to 24 hours to incorporate into the algorithm.<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Overview E-mail that flows into the server goes through several phases of filtering before final delivery, including: DNSBL lookups on handshake Deep protocol inspection DomainKeys\/SPF validation SpamAssassin filtering Whitelist management Hash-sharing systems (DCC &amp; Razor) Token-based regex\u00a0matching Markup filtering Bayesian filtering All steps in\u00a0the filtering process are automated, except for&#8230;<\/p>","protected":false},"author":1,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"ht-kb-category":[58],"ht-kb-tag":[],"class_list":["post-8516","ht_kb","type-ht_kb","status-publish","format-standard","has-post-thumbnail","hentry","ht_kb_category-e-mail"],"_links":{"self":[{"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb\/8516","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/comments?post=8516"}],"version-history":[{"count":1,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb\/8516\/revisions"}],"predecessor-version":[{"id":8517,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb\/8516\/revisions\/8517"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/media\/8518"}],"wp:attachment":[{"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/media?parent=8516"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb-category?post=8516"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/kb.okra.host\/de\/wp-json\/wp\/v2\/ht-kb-tag?post=8516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}