{"id":63,"date":"2021-04-13T08:20:05","date_gmt":"2021-04-13T06:20:05","guid":{"rendered":"https:\/\/georgekolios.psy.auth.gr\/?p=63"},"modified":"2021-04-13T08:21:06","modified_gmt":"2021-04-13T06:21:06","slug":"blocking-email-spam-with-postfix-smtp-server-virtualmin","status":"publish","type":"post","link":"https:\/\/georgekolios.psy.auth.gr\/index.php\/2021\/04\/13\/blocking-email-spam-with-postfix-smtp-server-virtualmin\/","title":{"rendered":"Blocking Email Spam with Postfix SMTP Server &#8211; Virtualmin"},"content":{"rendered":"\n<p>#Reject Email if SMTP Client Has no PTR record<br>#Reject Email if SMTP Client Hostname doesn\u2019t have valid A Record<br>#Reject Email If MAIL FROM Domain Has Neither MX Record Nor A Record<\/p>\n\n\n\n<p>smtpd_sender_restrictions =<br>permit_mynetworks<br>permit_sasl_authenticated<br>reject_unknown_sender_domain<br>reject_unknown_reverse_client_hostname<br>reject_unknown_client_hostname<\/p>\n\n\n\n<p>#Enable HELO\/EHLO Hostname Restrictions in Postfix<\/p>\n\n\n\n<p>smtpd_helo_required = yes<br>smtpd_helo_restrictions =<br>permit_mynetworks<br>permit_sasl_authenticated<br>reject_invalid_helo_hostname<br>reject_non_fqdn_helo_hostname<br>reject_unknown_helo_hostname<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p>More on  <a href=\"https:\/\/www.linuxbabe.com\/mail-server\/block-email-spam-postfix\" target=\"_blank\" rel=\"noreferrer noopener\">https:\/\/www.linuxbabe.com\/mail-server\/block-email-spam-postfix<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>#Reject Email if SMTP Client Has no PTR record#Reject Email if SMTP Client Hostname doesn\u2019t have valid A Record#Reject Email If MAIL FROM Domain Has Neither MX Record Nor A Record smtpd_sender_restrictions =permit_mynetworkspermit_sasl_authenticatedreject_unknown_sender_domainreject_unknown_reverse_client_hostnamereject_unknown_client_hostname #Enable HELO\/EHLO Hostname Restrictions in Postfix smtpd_helo_required = yessmtpd_helo_restrictions =permit_mynetworkspermit_sasl_authenticatedreject_invalid_helo_hostnamereject_non_fqdn_helo_hostnamereject_unknown_helo_hostname More on https:\/\/www.linuxbabe.com\/mail-server\/block-email-spam-postfix<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6,7],"tags":[],"class_list":["post-63","post","type-post","status-publish","format-standard","hentry","category-for-it","category-virtualmin"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/posts\/63","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/comments?post=63"}],"version-history":[{"count":3,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/posts\/63\/revisions"}],"predecessor-version":[{"id":66,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/posts\/63\/revisions\/66"}],"wp:attachment":[{"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/media?parent=63"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/categories?post=63"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/georgekolios.psy.auth.gr\/index.php\/wp-json\/wp\/v2\/tags?post=63"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}