{"id":18569,"date":"2026-03-31T08:34:41","date_gmt":"2026-03-31T06:34:41","guid":{"rendered":"https:\/\/webhosting.de\/reverse-dns-ptr-records-mail-hosting-authentifizierung-postfach\/"},"modified":"2026-03-31T08:34:41","modified_gmt":"2026-03-31T06:34:41","slug":"%e9%80%86%e5%bc%95%e3%81%8ddns-ptr%e3%83%ac%e3%82%b3%e3%83%bc%e3%83%89-%e3%83%a1%e3%83%bc%e3%83%ab%e3%83%9b%e3%82%b9%e3%83%86%e3%82%a3%e3%83%b3%e3%82%b0-%e8%aa%8d%e8%a8%bc%e3%83%a1%e3%83%bc%e3%83%ab","status":"publish","type":"post","link":"https:\/\/webhosting.de\/ja\/reverse-dns-ptr-records-mail-hosting-authentifizierung-postfach\/","title":{"rendered":"\u30ea\u30d0\u30fc\u30b9DNS\u3068PTR\u30ec\u30b3\u30fc\u30c9\uff1a\u4fe1\u983c\u6027\u306e\u9ad8\u3044\u30e1\u30fc\u30eb\u30db\u30b9\u30c6\u30a3\u30f3\u30b0\u306b\u4e0d\u53ef\u6b20\u306a\u57fa\u672c\u4e8b\u9805"},"content":{"rendered":"<p>\u9006DNS\u30e1\u30fc\u30eb\u30db\u30b9\u30c6\u30a3\u30f3\u30b0\u306f\u3001\u53d7\u4fe1\u30b5\u30fc\u30d0\u30fc\u304c\u63a5\u7d9a\u3092\u53d7\u3051\u5165\u308c\u308b\u304b\u3069\u3046\u304b\u3001\u30e1\u30c3\u30bb\u30fc\u30b8\u304c\u53d7\u4fe1\u7bb1\u306b\u5c4a\u304f\u304b\u3069\u3046\u304b\u3092\u6c7a\u5b9a\u3059\u308b\u3002\u3069\u306e\u3088\u3046\u306b <strong>\u30ea\u30d0\u30fc\u30b9DNS<\/strong>, PTR\u30ec\u30b3\u30fc\u30c9\u3068FCRDNS\u306e\u9023\u643a\u3001SMTP\u30d0\u30ca\u30fc\u306e\u5f79\u5272\u3001\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306e\u30bb\u30c3\u30c8\u30a2\u30c3\u30d7\u3067\u3059\u3050\u306b\u6ce8\u610f\u3059\u308b\u3053\u3068\u3002.<\/p>\n\n<h2>\u4e2d\u5fc3\u70b9<\/h2>\n\n<ul>\n  <li><strong>\u30ea\u30d0\u30fc\u30b9DNS<\/strong> IP\u2192\u30db\u30b9\u30c8\u540d\u3092\u5909\u63db\u3057\u3001\u4e2d\u592e\u306e\u4fe1\u983c\u30b7\u30b0\u30ca\u30eb\u3092\u63d0\u4f9b\u3059\u308b\u3002.<\/li>\n  <li><strong>PTR\u30ec\u30b3\u30fc\u30c9<\/strong> \u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306b\u3042\u308a\u3001\u30e1\u30fc\u30eb\u30b5\u30fc\u30d0\u30fc\u306eFQDN\u3068\u4e00\u81f4\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002.<\/li>\n  <li><strong>FCRDNS<\/strong> \u306f\u3001\u30db\u30b9\u30c8\u540d\u304c\u518d\u3073\u540c\u3058IP\u3092\u6307\u3057\u3066\u3044\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3059\u308b\u3002.<\/li>\n  <li><strong>SMTP\u30d0\u30ca\u30fc<\/strong> (HELO\/EHLO\uff09\u3068PTR\u306f\u6b63\u78ba\u306b\u4e00\u81f4\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002.<\/li>\n  <li><strong>\u8a55\u5224<\/strong> \u30e1\u30ea\u30c3\u30c8\u3001\u914d\u9001\u306e\u554f\u984c\u3001\u30d6\u30e9\u30c3\u30af\u30ea\u30b9\u30c8\u306f\u7a00\u306b\u306a\u3063\u3066\u304d\u3066\u3044\u308b\u3002.<\/li>\n<\/ul>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img fetchpriority=\"high\" decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/mailhosting-server-2569.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>\n\n\n<h2>\u30ea\u30d0\u30fc\u30b9DNS\u306e\u7c21\u5358\u306a\u8aac\u660e<\/h2>\n\n<p>\u30d5\u30a9\u30ef\u30fc\u30c9DNS\u306f\u30c9\u30e1\u30a4\u30f3\u3092IP\u306b\u89e3\u6c7a\u3059\u308b\u3002 <strong>\u9006\u5f15\u304d<\/strong> \u306f\u9006\u65b9\u5411\u306e\u5f79\u5272\u3092\u679c\u305f\u3057\u3001IP\u3092\u30db\u30b9\u30c8\u540d\u306b\u30de\u30c3\u30d4\u30f3\u30b0\u3059\u308b\u3002IPv4\u306ein-addr.arpa\u3084IPv6\u306eip6.arpa\u306a\u3069\u3001PTR\u30ec\u30b3\u30fc\u30c9\u3092\u542b\u3080\u7279\u5225\u306a\u30be\u30fc\u30f3\u306f\u3001\u3053\u306e\u76ee\u7684\u306e\u305f\u3081\u306b\u5b58\u5728\u3059\u308b\u3002\u30e1\u30fc\u30eb\u53d7\u4fe1\u8005\u306f\u3001\u9001\u4fe1\u30b7\u30b9\u30c6\u30e0\u306e\u8eab\u5143\u3092\u3088\u308a\u3088\u304f\u8a55\u4fa1\u3059\u308b\u305f\u3081\u306b\u3001\u7740\u4fe1\u63a5\u7d9a\u306b\u5bfe\u3057\u3066\u3053\u306ePTR\u60c5\u5831\u3092\u7167\u4f1a\u3059\u308b\u3002\u7b54\u3048\u304c\u6b63\u3057\u3051\u308c\u3070\u3001\u9001\u4fe1\u5143\u306b\u5bfe\u3059\u308b\u4fe1\u983c\u304c\u9ad8\u307e\u308a\u3001\u691c\u8a3c\u30d7\u30ed\u30bb\u30b9\u304c\u3088\u308a\u8fc5\u901f\u306b\u5b9f\u884c\u3055\u308c\u308b\u3002\u30a8\u30f3\u30c8\u30ea\u304c\u306a\u304b\u3063\u305f\u308a\u3001\u7121\u610f\u5473\u306a\u60c5\u5831\u3092\u63d0\u4f9b\u3057\u3066\u3044\u308b\u5834\u5408\u306f\u3001\u8a55\u4fa1\u304c\u53b3\u3057\u304f\u306a\u308a\u3001\u3055\u3089\u306a\u308b\u30d5\u30a3\u30eb\u30bf\u304c\u9069\u7528\u3055\u308c\u308b\u3002.<\/p>\n\n<h2>PTR\u30ec\u30b3\u30fc\u30c9\u3092\u6b63\u3057\u304f\u8a2d\u5b9a\u3059\u308b<\/h2>\n\n<p>\u79c1\u306f\u307e\u305a\u3001\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u5074\u306ePTR\u30ec\u30b3\u30fc\u30c9\u304c\u6b21\u306e\u3088\u3046\u306b\u6b63\u3057\u304f\u30de\u30c3\u30d4\u30f3\u30b0\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3059\u308b\u3002 <strong>\u304b\u3093\u305c\u3093\u3057\u3085\u3046\u3057\u3087\u304f\u30c9\u30e1\u30a4\u30f3\u3081\u3044<\/strong> \u79c1\u306e\u30e1\u30fc\u30eb\u30b5\u30fc\u30d0\u30fc\u306e\u30ea\u30d0\u30fc\u30b9\u30be\u30fc\u30f3\u306f\u30c9\u30e1\u30a4\u30f3\u81ea\u8eab\u306e\u30be\u30fc\u30f3\u30d5\u30a1\u30a4\u30eb\u306b\u3088\u3063\u3066\u7ba1\u7406\u3055\u308c\u308b\u306e\u3067\u306f\u306a\u304f\u3001IP\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30aa\u30da\u30ec\u30fc\u30bf\u307e\u305f\u306f\u30db\u30b9\u30c8\u306b\u3088\u3063\u3066\u7ba1\u7406\u3055\u308c\u308b\u3002\u3057\u305f\u304c\u3063\u3066\u3001\u79c1\u306f104.168.205.10\u2192mail.example.com\u306e\u3088\u3046\u306b\u660e\u78ba\u306a\u5272\u308a\u5f53\u3066\u3092\u884c\u3044\u3001mail.example.com\u306e\u9806\u65b9\u5411\u691c\u7d22\u304c104.168.205.10\u3092\u6307\u3057\u3066\u3044\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b\u3002\u3053\u306e\u4e21\u9762\u304b\u3089\u306e\u78ba\u8a8d\u3060\u3051\u304c\u3001\u8a2d\u5b9a\u3092\u672c\u5f53\u306b\u4e00\u8cab\u3057\u305f\u3082\u306e\u306b\u3059\u308b\u3002\u30db\u30b9\u30c8\u540d\u3068\u30d0\u30ca\u30fc\u304c\u4e00\u81f4\u3057\u306a\u3044\u3068\u3001\u30b2\u30fc\u30c8\u30a6\u30a7\u30a4\u3067\u4e0d\u4fe1\u304c\u751f\u3058\u3001\u3057\u3070\u3057\u3070\u76f4\u63a5\u62d2\u7d76\u3055\u308c\u308b\u3053\u3068\u306b\u306a\u308b\u3002.<\/p>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/ReverseDNS_PTR_Grundlagen_7345.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>\n\n\n<h2>FCRDNS\u3068SMTP\u30d0\u30ca\u30fc\u3092\u304d\u308c\u3044\u306b\u8abf\u548c\u3055\u305b\u308b<\/h2>\n\n<p>\u63a5\u7d9a\u3092\u78ba\u7acb\u3059\u308b\u969b\u3001\u79c1\u306eMTA\u306fEHLO\/HELO\u3067\u76f8\u624b\u306b\u6328\u62f6\u3057\u3001\u6b21\u306e\u3088\u3046\u306b\u660e\u78ba\u306b\u8ff0\u3079\u308b\u3002 <strong>\u30db\u30b9\u30c8\u540d<\/strong>. .\u3053\u306e\u540d\u524d\u306f\u3001PTR\u306b\u683c\u7d0d\u3055\u308c\u3066\u3044\u308bFQDN\u306b\u6b63\u78ba\u306b\u5bfe\u5fdc\u3057\u3066\u3044\u306a\u3051\u308c\u3070\u306a\u308a\u307e\u305b\u3093\u3002\u305d\u3046\u3067\u306a\u3044\u5834\u5408\u3001\u591a\u304f\u306e\u30b7\u30b9\u30c6\u30e0\u304c\u300cReverse DNS\/SMTP Banner mismatch\uff08\u9006DNS\/SMTP\u30d0\u30ca\u30fc\u306e\u4e0d\u4e00\u81f4\uff09\u300d\u3092\u5831\u544a\u3057\u307e\u3059\u3002\u307e\u305f\u3001FCRDNS\u3082\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3059\uff1aPTR\u306f\u30db\u30b9\u30c8\u540d\u3092\u6307\u3057\u3001\u305d\u306eA\/AAA\u306f\u5143\u306eIP\u3092\u6307\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u306f\u8aa4\u5206\u985e\u3092\u9632\u304e\u3001\u30b5\u30fc\u30d0\u30fc\u304c\u8b58\u5225\u53ef\u80fd\u3067\u7ba1\u7406\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u3092\u793a\u3057\u307e\u3059\u3002\u5bfe\u7167\u7684\u306b\u3001\u30d7\u30ed\u30d0\u30a4\u30c0\u304b\u3089\u306e\u4e00\u822c\u7684\u306arDNS\u540d\u306f\u3001\u533f\u540d\u30bd\u30fc\u30b9\u306e\u3088\u3046\u306b\u632f\u308b\u821e\u3044\u3001\u3057\u3070\u3057\u3070\u3088\u308a\u53b3\u3057\u3044\u30d5\u30a3\u30eb\u30bf\u3092\u30c8\u30ea\u30ac\u3057\u307e\u3059\u3002.<\/p>\n\n<h2>\u30e1\u30fc\u30eb\u30b5\u30fc\u30d0\u30fc\u306e\u8a55\u4fa1\u3068\u914d\u4fe1\u80fd\u529b<\/h2>\n\n<p>\u79c1\u306f\u3001\u9001\u308a\u4e3b\u306e\u8eab\u5143\u3092\u660e\u78ba\u306b\u78ba\u8a8d\u3059\u308b\u3053\u3068\u3067\u3001\u826f\u597d\u306a\u914d\u9054\u7387\u3092\u9054\u6210\u3057\u3066\u3044\u308b\u3002 <strong>\u4fe1\u53f7<\/strong> \u4e00\u8cab\u3057\u3066\u3044\u308b\u3002\u591a\u304f\u306e\u53d7\u4fe1\u8005\u306f\u3001PTR\u3001FCRDNS\u3001\u30d0\u30ca\u30fc\u3092\u3001\u3055\u3089\u306a\u308b\u30c1\u30a7\u30c3\u30af\u304c\u6709\u52b9\u306b\u306a\u308b\u524d\u306e\u6700\u521d\u306e\u969c\u58c1\u3068\u8003\u3048\u3066\u3044\u307e\u3059\u3002\u3053\u3053\u3067\u9069\u5207\u306b\u50cd\u3051\u3070\u3001\u30d0\u30a6\u30f3\u30b9\u3001\u30b9\u30d1\u30e0\u30d5\u30a9\u30eb\u30c0\u3067\u306e\u30c8\u30ea\u30a2\u30fc\u30b8\u3001\u4e0d\u5fc5\u8981\u306a\u9045\u5ef6\u3092\u5927\u5e45\u306b\u6e1b\u3089\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u914d\u4fe1\u30eb\u30fc\u30c8\u3068IP\u30ec\u30d4\u30e5\u30c6\u30fc\u30b7\u30e7\u30f3\u306e\u3088\u308a\u8a73\u7d30\u306a\u6700\u9069\u5316\u306b\u3064\u3044\u3066\u306f\u3001\u79c1\u306f\u4ee5\u4e0b\u306e\u6982\u8981\u306b\u3042\u308b\u3088\u3046\u306a\u6226\u7565\u3092\u4f7f\u7528\u3057\u3066\u3044\u307e\u3059\u3002 <a href=\"https:\/\/webhosting.de\/ja\/e%e3%83%a1%e3%83%bc%e3%83%ab-%e3%83%9b%e3%82%b9%e3%83%86%e3%82%a3%e3%83%b3%e3%82%b0-%e3%82%a4%e3%83%b3%e3%83%95%e3%83%a9-%e8%a9%95%e5%88%a4-%e9%85%8d%e4%bf%a1%e6%80%a7-ipmailboost\/\">\u96fb\u5b50\u30e1\u30fc\u30eb\u306e\u914d\u4fe1\u6027<\/a>. .\u4e0d\u78ba\u5b9f\u6027\u3092\u6e1b\u3089\u3059\u3053\u3068\u306f\u3001\u30d5\u30a3\u30eb\u30bf\u30fc\u304c\u6b63\u5f53\u306a\u30e1\u30fc\u30eb\u3068\u5371\u967a\u306a\u30d1\u30bf\u30fc\u30f3\u3092\u5206\u96e2\u3059\u308b\u306e\u306b\u5f79\u7acb\u3064\u3002.<\/p>\n\n<h2>\u3088\u304f\u3042\u308b\u30a8\u30e9\u30fc\u3068\u30d6\u30e9\u30c3\u30af\u30ea\u30b9\u30c8<\/h2>\n\n<p>\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30fb\u30a2\u30af\u30bb\u30b9\u30fb\u30dd\u30a4\u30f3\u30c8\u306e\u3088\u3046\u306b\u898b\u3048\u308bPTR\u304c\u306a\u3044\u3001\u3042\u308b\u3044\u306f\u4e00\u822c\u7684\u306aPTR\u3092\u3088\u304f\u898b\u304b\u3051\u308b\u3002 <strong>\u30b9\u30d1\u30e0\u30d5\u30a3\u30eb\u30bf<\/strong> \u30c8\u30ea\u30ac\u30fc\u3068\u306a\u308b\u3002\u660e\u78ba\u306a\u30d5\u30a9\u30ef\u30fc\u30c9\u30de\u30c3\u30d4\u30f3\u30b0\u306e\u306a\u3044\u30011\u3064\u306eIP\u306b\u5bfe\u3059\u308b\u8907\u6570\u306ePTR\u3082\u77db\u76fe\u306b\u3064\u306a\u304c\u308b\u3002\u7570\u306a\u308b\u540d\u524d\u306eHELO\u304c\u8ffd\u52a0\u3055\u308c\u305f\u5834\u5408\u3001\u30d6\u30ed\u30c3\u30ad\u30f3\u30b0\u306e\u30ea\u30b9\u30af\u306f\u5287\u7684\u306b\u5897\u52a0\u3059\u308b\u3002\u3057\u305f\u304c\u3063\u3066\u3001\u79c1\u306frDNS\u306e\u554f\u984c\u3092\u793a\u30594xx\/5xx\u30ec\u30b9\u30dd\u30f3\u30b9\u306b\u3064\u3044\u3066\u7279\u306b\u30ed\u30b0\u3092\u30c1\u30a7\u30c3\u30af\u3057\u307e\u3059\u3002\u539f\u56e0\u3092\u7406\u89e3\u3057\u305f\u3044\u5834\u5408\u306f\u3001\u5178\u578b\u7684\u306a\u30c8\u30e9\u30c3\u30d7\u3068\u30d1\u30b9\u3092\u898b\u3064\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3001, <a href=\"https:\/\/webhosting.de\/ja\/%e3%83%a1%e3%83%bc%e3%83%ab%e3%82%b5%e3%83%bc%e3%83%90%e3%81%aeip%e3%81%8c%e3%83%96%e3%83%a9%e3%83%83%e3%82%af%e3%83%aa%e3%82%b9%e3%83%88%e3%81%aemailfix%e3%81%a7%e4%b8%80%e7%b7%92%e3%81%ab%e3%81%aa\/\">\u30d6\u30e9\u30c3\u30af\u30ea\u30b9\u30c8\u3092\u907f\u3051\u308b<\/a>, \u30b3\u30f3\u30d1\u30af\u30c8\u306a\u5206\u6790\u3067.<\/p>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/reverse-dns-ptr-records-4234.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>\n\n\n<h2>\u5b9f\u8df5\uff1a\u691c\u67fb\u3068\u8a3a\u65ad<\/h2>\n\n<p>\u78ba\u5b9f\u306a\u914d\u9054\u306e\u305f\u3081\u306b\u3001\u79c1\u306f\u5b9a\u671f\u7684\u306b\u30bb\u30c3\u30c8\u30a2\u30c3\u30d7\u3092\u30c6\u30b9\u30c8\u3057\u3001\u3059\u3079\u3066\u306e\u914d\u9054\u3092\u8a18\u9332\u3057\u3066\u3044\u308b\u3002 <strong>\u4fee\u6b63<\/strong>. .\u6700\u521d\u306bPTR\u30eb\u30c3\u30af\u30a2\u30c3\u30d7\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3001\u6b21\u306b\u30d5\u30a9\u30ef\u30fc\u30c9\u30eb\u30c3\u30af\u30a2\u30c3\u30d7\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3001\u6b21\u306b\u30d0\u30ca\u30fc\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3001\u6700\u5f8c\u306b\u8a8d\u8a3c\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u3002\u3053\u3046\u3059\u308b\u3053\u3068\u3067\u3001\u500b\u3005\u306e\u8a73\u7d30\u306b\u8ff7\u3046\u3053\u3068\u306a\u304f\u3001\u30c1\u30a7\u30fc\u30f3\u306e\u30a8\u30e9\u30fc\u3092\u7d20\u65e9\u304f\u8a8d\u8b58\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002\u660e\u78ba\u306a\u30c6\u30b9\u30c8\u30fb\u30d1\u30b9\u306f\u6642\u9593\u3092\u7bc0\u7d04\u3057\u3001\u5404\u30b3\u30f3\u30d5\u30a3\u30ae\u30e5\u30ec\u30fc\u30b7\u30e7\u30f3\u8abf\u6574\u5f8c\u306e\u30d6\u30e9\u30a4\u30f3\u30c9\u30fb\u30d5\u30e9\u30a4\u30c8\u3092\u907f\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002\u4ee5\u4e0b\u306e\u8868\u306f\u3001\u4e00\u822c\u7684\u306a\u30c1\u30a7\u30c3\u30af\u9805\u76ee\u3068\u3001\u305d\u308c\u304c\u91cd\u8981\u306a\u7406\u7531\u3001\u305d\u3057\u3066\u79c1\u304c\u898b\u305f\u3044\u7d50\u679c\u3092\u793a\u3057\u3066\u3044\u308b\u3002.<\/p>\n\n<table>\n  <thead>\n    <tr>\n      <th>\u5be9\u67fb<\/th>\n      <th>\u306a\u305c<\/th>\n      <th>\u30b3\u30de\u30f3\u30c9\/\u4f8b<\/th>\n      <th>\u671f\u5f85\u3055\u308c\u308b\u7d50\u679c<\/th>\n    <\/tr>\n  <\/thead>\n  <tbody>\n    <tr>\n      <td>PTR\u30eb\u30c3\u30af\u30a2\u30c3\u30d7<\/td>\n      <td>IP\u304b\u3089\u30db\u30b9\u30c8\u540d\u3092\u6c7a\u5b9a<\/td>\n      <td>dig -x 104.168.205.10 +short<\/td>\n      <td>mail.example.com<\/td>\n    <\/tr>\n    <tr>\n      <td>\u30d5\u30a9\u30ef\u30fc\u30c9\u30fb\u30eb\u30c3\u30af\u30a2\u30c3\u30d7<\/td>\n      <td>FCRDNS\u306e\u78ba\u8a8d<\/td>\n      <td>dig A mail.example.com +short<\/td>\n      <td>104.168.205.10<\/td>\n    <\/tr>\n    <tr>\n      <td>SMTP\u30d0\u30ca\u30fc<\/td>\n      <td>EHLO\u540d\u3092\u30c1\u30a7\u30c3\u30af<\/td>\n      <td>openssl s_client -starttls smtp -connect mx.example.net:25<\/td>\n      <td>EHLO mail.example.com<\/td>\n    <\/tr>\n    <tr>\n      <td>SPF<\/td>\n      <td>\u9001\u4fe1IP\u306e\u8a8d\u53ef<\/td>\n      <td>dig TXT example.com +short<\/td>\n      <td>v=spf1 ip4:104.168.205.10 -all<\/td>\n    <\/tr>\n    <tr>\n      <td>\u30c7\u30a3\u30fc\u30b1\u30fc\u30a2\u30a4\u30a8\u30e0<\/td>\n      <td>\u7f72\u540d\u306e\u691c\u8a3c<\/td>\n      <td>dig TXT selector._domainkey.example.com +short<\/td>\n      <td>v=DKIM1; p=...<\/td>\n    <\/tr>\n    <tr>\n      <td>\uff24\uff2d\uff21\uff32\uff23<\/td>\n      <td>\u65b9\u91dd\u3068\u5831\u544a<\/td>\n      <td>dig TXT _dmarc.example.com +short<\/td>\n      <td>v=DMARC1\u3001p=\u691c\u75ab<\/td>\n    <\/tr>\n  <\/tbody>\n<\/table>\n\n<h2>DNS\u30a8\u30b3\u30b7\u30b9\u30c6\u30e0\u306e\u8abf\u6574\uff1aSPF\u3001DKIM\u3001DMARC\u3001MX<\/h2>\n\n<p>PTR\u306f\u30b9\u30bf\u30fc\u30c8\u306e\u5408\u56f3\u3060\u304c\u3001\u79c1\u306f\u307e\u305f\u3001\u9001\u4fe1\u8005\u306e\u8eab\u5143\u3092\u57fa\u306b\u3059\u308b\u3002 <strong>SPF<\/strong>, DKIM\u3068DMARC\u3002SPF\u306f\u9001\u4fe1IP\u3092\u8a8d\u8a3c\u3057\u3001DKIM\u306f\u30e1\u30c3\u30bb\u30fc\u30b8\u306e\u4fe1\u983c\u6027\u3092\u8a3c\u660e\u3057\u3001DMARC\u306f\u30dd\u30ea\u30b7\u30fc\u3068\u8a55\u4fa1\u3092\u675f\u306d\u308b\u3002\u79c1\u306f\u3001\u9001\u4fe1\u5143\u30c9\u30e1\u30a4\u30f3\u3001DKIM\u30c9\u30e1\u30a4\u30f3\u3001SPF\u30c9\u30e1\u30a4\u30f3\u304c\u4e00\u7dd2\u306b\u306a\u308b\u3088\u3046\u306b\u3001\u9069\u5207\u306a\u914d\u7f6e\u306b\u6ce8\u610f\u3092\u6255\u3063\u3066\u3044\u307e\u3059\u3002\u307e\u305f\u3001MX\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u610f\u8b58\u7684\u306b\u8a08\u753b\u3057\u3001\u512a\u5148\u9806\u4f4d\u3092\u304d\u308c\u3044\u306b\u3057\u3066\u3044\u307e\u3059\u3002 <a href=\"https:\/\/webhosting.de\/ja\/mx%e3%83%ac%e3%82%b3%e3%83%bc%e3%83%89%e3%81%ae%e5%84%aa%e5%85%88%e9%a0%86%e4%bd%8d%e4%bb%98%e3%81%91-%e3%83%a1%e3%83%bc%e3%83%ab%e3%83%ab%e3%83%bc%e3%83%86%e3%82%a3%e3%83%b3%e3%82%b0-%e3%83%9b\/\">MX\u30ec\u30b3\u30fc\u30c9\u306e\u512a\u5148\u9806\u4f4d<\/a>. .\u4fe1\u53f7\u306e\u4e00\u8cab\u6027\u3092\u4fdd\u3064\u3053\u3068\u3067\u3001\u30d5\u30a3\u30eb\u30bf\u30fc\u306b\u660e\u78ba\u306a\u8b58\u5225\u60c5\u5831\u3092\u63d0\u4f9b\u3057\u3001\u8aa4\u3063\u305f\u5224\u65ad\u3092\u5927\u5e45\u306b\u6e1b\u3089\u3059\u3053\u3068\u304c\u3067\u304d\u308b\u3002.<\/p>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/dns_ptr_grundlagen_office_1324.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>\n\n\n<h2>IPv4\u3068IPv6\u306e\u6bd4\u8f03\uff1aPTR\u306e\u7279\u6b8a\u6a5f\u80fd<\/h2>\n\n<p>IPv6\u3067\u306f\u3001ip6.arpa\u3092\u4f7f\u3044\u3001PTR\u3092\u30cb\u30d6\u30eb\u8a18\u6cd5\u3067\u8a2d\u5b9a\u3057\u307e\u3059\u3002 <strong>\u6c7a\u8b70<\/strong> \u304c\u6709\u52b9\u306b\u306a\u308a\u307e\u3059\u3002FCRDNS\u3092\u96e3\u3057\u304f\u3057\u3001\u30d5\u30a3\u30eb\u30bf\u3092\u6df7\u4e71\u3055\u305b\u308b\u306e\u3067\u3001\u30a2\u30c9\u30ec\u30b9\u3054\u3068\u306b\u8907\u6570\u306ePTR\u3092\u4f7f\u3046\u3053\u3068\u306f\u907f\u3051\u3066\u3044\u308b\u3002\u8907\u6570\u306ev6\u30a2\u30c9\u30ec\u30b9\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u3001\u3069\u306eIP\u304c\u30a2\u30af\u30c6\u30a3\u30d6\u306b\u9001\u4fe1\u3057\u3066\u3044\u308b\u304b\u3092\u5224\u65ad\u3057\u3001PTR\u3068\u8ee2\u9001\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u307e\u3055\u306b\u3053\u306eIP\u306b\u5272\u308a\u5f53\u3066\u307e\u3059\u3002\u79c1\u306f\u3001\u751f\u7523\u7684\u306a\u30c7\u30a3\u30b9\u30d1\u30c3\u30c1\u30d1\u30b9\u306e\u305f\u3081\u306b\u3001\u56fa\u5b9aPTR\u5272\u308a\u5f53\u3066\u306e\u306a\u3044\u30c0\u30a4\u30ca\u30df\u30c3\u30afv6\u30ec\u30f3\u30b8\u3092\u907f\u3051\u3066\u3044\u308b\u3002\u3053\u3046\u3059\u308b\u3053\u3068\u3067\u3001\u8907\u6570\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u304c\u4e26\u884c\u3057\u3066\u52d5\u4f5c\u3057\u3066\u3044\u308b\u5834\u5408\u3067\u3082\u3001\u8eab\u5143\u3092\u660e\u78ba\u306b\u4fdd\u3064\u3053\u3068\u304c\u3067\u304d\u308b\u3002.<\/p>\n\n<h2>rDNS\u306e\u6b63\u3057\u3044\u30db\u30b9\u30c8\u540d\u3092\u9078\u629e\u3059\u308b<\/h2>\n\n<p>mail.example.com\u306e\u3088\u3046\u306a\u56fa\u5b9aFQDN\u3092\u9078\u3073\u3001\u6b21\u306e\u3088\u3046\u306b\u3057\u307e\u3059\u3002 <strong>\u4e0d\u5909<\/strong>. .\u30a2\u30f3\u30c0\u30fc\u30b9\u30b3\u30a2\u306f\u907f\u3051\u3001\u30cf\u30a4\u30d5\u30f3\u306f\u91cd\u8981\u3067\u306f\u306a\u304f\u3001rDNS\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u3067\u306f\u30ef\u30a4\u30eb\u30c9\u30ab\u30fc\u30c9\u3084CNAME\u306f\u4f7f\u7528\u3057\u306a\u3044\u3002TLS\u306e\u5834\u5408\u3001\u8a3c\u660e\u66f8\u306fEHLO\u540d\u3068\u4e00\u81f4\u3059\u308b\u306e\u3067\u3001MTA-STS\u3068DANE\/STARTTLS\u306e\u30c1\u30a7\u30c3\u30af\u306f\u304d\u308c\u3044\u306b\u901a\u904e\u3059\u308b\u3002\u8907\u6570\u306eMTA\u304c\u5b58\u5728\u3059\u308b\u5834\u5408\u3001\u305d\u308c\u305e\u308c\u306b\u72ec\u81ea\u306eIP\u3068\u72ec\u81ea\u306ePTR\u3092\u6301\u3064\u30db\u30b9\u30c8\u540d\u3092\u4e0e\u3048\u308b\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u30c7\u30a3\u30b9\u30d1\u30c3\u30c1\u30d1\u30b9\u3092\u5206\u96e2\u3057\u3001\u554f\u984c\u3092\u5207\u308a\u5206\u3051\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002.<\/p>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/dns_ptr_grundlagen_7382.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>\n\n\n<h2>\u76e3\u8996\u3001\u6e2c\u5b9a\u57fa\u6e96\u3001\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9<\/h2>\n\n<p>\u672c\u756a\u7a3c\u52d5\u5f8c\u3082\u3001\u30d0\u30a6\u30f3\u30b9\u3001\u914d\u4fe1\u6642\u9593\u3001\u30b9\u30d1\u30e0\u7387\u3092\u7d99\u7d9a\u7684\u306b\u76e3\u8996\u3057\u3066\u3044\u307e\u3059\u3002 <strong>\u4fe1\u53f7<\/strong> \u30e1\u30fc\u30eb\u306e\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u304c\u5909\u52d5\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u79c1\u306fRBL\u30c1\u30a7\u30c3\u30af\u3092\u4f7f\u3044\u3001rDNS\u3092\u5b9a\u671f\u7684\u306b\u30c1\u30a7\u30c3\u30af\u3057\u3001\u30d0\u30ca\u30fc\u3068TLS\u306e\u8a73\u7d30\u3092\u8a18\u9332\u3057\u3066\u3044\u307e\u3059\u3002\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3084\u65b0\u3057\u3044IP\u3078\u306e\u5909\u66f4\u306f\u3059\u3050\u306b\u6587\u66f8\u5316\u3057\u3001\u30c6\u30b9\u30c8\u30c1\u30a7\u30fc\u30f3\u3092\u7e70\u308a\u8fd4\u3057\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u30ea\u30b9\u30c8\u30a8\u30f3\u30c8\u30ea\u3084\u3088\u308a\u53b3\u683c\u306a\u30d5\u30a3\u30eb\u30bf\u30fc\u304c\u914d\u4fe1\u306b\u9855\u8457\u306a\u5f71\u97ff\u3092\u4e0e\u3048\u308b\u524d\u306b\u3001\u65e9\u671f\u306b\u5bfe\u5fdc\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u9031\u306b\u4e00\u5ea6\u306e\u5c0f\u3055\u306a\u30c1\u30a7\u30c3\u30af\u3067\u3001\u5f8c\u3067\u6642\u9593\u306e\u304b\u304b\u308b\u6839\u672c\u539f\u56e0\u306e\u5206\u6790\u3092\u3059\u308b\u624b\u9593\u304c\u7701\u3051\u307e\u3059\u3002.<\/p>\n\n<h2>\u30d7\u30ed\u30d0\u30a4\u30c0\u306b\u304a\u3051\u308b\u9006\u30c7\u30ea\u30b2\u30fc\u30b7\u30e7\u30f3\u306e\u305f\u3081\u306e\u30af\u30ea\u30fc\u30f3\u306a\u30bd\u30ea\u30e5\u30fc\u30b7\u30e7\u30f3\uff08RFC 2317\uff09<\/h2>\n\n<p>\u79c1\u304c\u5b8c\u5168\u306a\/24\u30d6\u30ed\u30c3\u30af\u3092\u6240\u6709\u3057\u3066\u3044\u308b\u5834\u5408\u3001\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306f\u79c1\u306bin-addr.arpa\u30be\u30fc\u30f3\u5168\u4f53\u3092\u59d4\u8b72\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3057\u304b\u3057\u3001\u79c1\u306f\/29\u3084\/28\u306e\u3088\u3046\u306a\u5c0f\u3055\u306a\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u3092\u3088\u304f\u4f7f\u3044\u307e\u3059\u3002 <strong>RFC 2317<\/strong> (\u30af\u30e9\u30b9\u30ec\u30b9\u59d4\u4efb\uff09\uff1a(\u30af\u30e9\u30b9\u30ec\u30b9\u59d4\u4efb): \u30d7\u30ed\u30d0\u30a4\u30c0\u306f\u30ea\u30d0\u30fc\u30b9\u30be\u30fc\u30f3\u306b\u5f71\u97ff\u3092\u53d7\u3051\u308b\u30a2\u30c9\u30ec\u30b9\u306eCNAME\u3092\u4f5c\u6210\u3057\u3001\u305d\u306eCNAME\u306f\u79c1\u304c\u7ba1\u7406\u3059\u308b\u30b5\u30d6\u30be\u30fc\u30f3\u3092\u6307\u3059\u3002\u5b9f\u969b\u306ePTR\u30ec\u30b3\u30fc\u30c9\u306f\u79c1\u304c\u7ba1\u7406\u3057\u3066\u3044\u307e\u3059\u3002\u4f8b\uff1a104.168.205.8\/29\u306e\u5834\u5408\u300110.205.168.104.in-addr.arpa\u306fCNAME\u7d4c\u7531\u306710.8-15.205.168.104.in-addr.arpa\u3092\u6307\u3057\u3001mail.example.com\u3078\u306e\u79c1\u306ePTR\u306f\u3053\u306e\u30b5\u30d6\u30be\u30fc\u30f3\u306b\u3042\u308a\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u6bce\u56de\u30c1\u30b1\u30c3\u30c8\u3092\u958b\u304f\u3053\u3068\u306a\u304f\u3001\u81ea\u5206\u3067\u5909\u66f4\u3092\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002.<\/p>\n\n<h2>NAT\u3001\u30ed\u30fc\u30c9\u30d0\u30e9\u30f3\u30b5\u30fc\u3001\u30ea\u30ec\u30fc\uff1a\u3069\u306eIP\u3092\u30ab\u30a6\u30f3\u30c8\u3059\u308b\u304b\uff1f<\/h2>\n\n<p>\u79c1\u306eMTA\u304cNAT\u307e\u305f\u306f\u30a2\u30a6\u30c8\u30d0\u30a6\u30f3\u30c9\u30ed\u30fc\u30c9\u30d0\u30e9\u30f3\u30b5\u30fc\u306e\u80cc\u5f8c\u306b\u3042\u308b\u5834\u5408\u3001\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002 <strong>\u30d1\u30d6\u30ea\u30c3\u30af\u30bd\u30fc\u30b9IP<\/strong> \u8a72\u5f53\u3059\u308b\u3002\u3053\u306eIP\u306b\u6b63\u78ba\u306brDNS\u3092\u8a2d\u5b9a\u3057\u3001EHLO\u3068\u8a3c\u660e\u66f8\u3092\u4e00\u81f4\u3055\u305b\u308b\u3002Postfix\u3067\u306f\u3001\u9001\u4fe1\u63a5\u7d9a\u7528\u306bEHLO\u540d\u3092\u660e\u793a\u7684\u306b\u8a2d\u5b9a\u3057\uff08smtp_helo_name\uff09\u3001\u30aa\u30d7\u30b7\u30e7\u30f3\u3067\u56fa\u5b9a\u9001\u4fe1\u8005IP\u3092\u30d0\u30a4\u30f3\u30c9\u3059\u308b\uff08smtp_bind_address\/6\uff09\u3002Exim\u3067\u306finterface\/helo_data\u3092\u5b9a\u7fa9\u3057\u307e\u3059\u3002\u3082\u3057\u79c1\u304csmarthost\u3092\u4f7f\u3046\u306a\u3089\u3001\u305d\u306erDNS\u3068\u30ec\u30d4\u30e5\u30c6\u30fc\u30b7\u30e7\u30f3\u30ab\u30a6\u30f3\u30c8\u3092\u4f7f\u3046\u3002\u79c1\u306fReceived\u30d8\u30c3\u30c0\u3067\u3069\u306e\u30db\u30c3\u30d7\u30c1\u30a7\u30fc\u30f3\u304c\u898b\u3048\u308b\u304b\u3092\u30c1\u30a7\u30c3\u30af\u3057\u3001\u30eb\u30fc\u30c8\u5168\u4f53\u3067\u540d\u524d\u3068IP\u3092\u8abf\u548c\u3055\u305b\u307e\u3059\u3002.<\/p>\n\n<h2>TTL\u3001\u30d7\u30ed\u30d1\u30b2\u30fc\u30b7\u30e7\u30f3\u3001\u5909\u66f4\u7ba1\u7406<\/h2>\n\n<p>DNS\u306e\u5909\u66f4\u306b\u306f\u6642\u9593\u304c\u304b\u304b\u308b\u3002\u79c1\u306f\u79fb\u8ee2\u306e\u524d\u306b\u3001A\/AAA\u3068PTR\u306eTTL\u3092\u4e00\u6642\u7684\u306b\u4e0b\u3052\uff08\u4f8b\u3048\u3070300\uff5e900\u79d2\uff09\u3001\u5207\u308a\u66ff\u3048\u3092\u5b9f\u884c\u3057\u3001\u305d\u306e\u5f8c\u3001\u518d\u5ea6\u3001\u5805\u7262\u306a\u5024\uff083600\uff5e86400\u79d2\uff09\u307e\u3067\u4e0a\u3052\u307e\u3059\u3002\u79c1\u306f <strong>\u4f1d\u642c\u6bb5\u968e<\/strong> \u5927\u624b\u306e\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306f\u7a4d\u6975\u7684\u306b\u30ad\u30e3\u30c3\u30b7\u30e5\u3057\u3066\u3044\u308b\u3002\u5927\u624b\u306e\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306f\u7a4d\u6975\u7684\u306b\u30ad\u30e3\u30c3\u30b7\u30e5\u3092\u884c\u3046\u306e\u3067\u3001\u914d\u4fe1\u306e\u554f\u984c\u3092\u4ed6\u306e\u539f\u56e0\u306e\u305b\u3044\u306b\u3059\u308b\u524d\u306b\u3001\u79c1\u306f\u6570\u6642\u9593\u5f85\u3064\u3053\u3068\u306b\u3057\u3066\u3044\u308b\u3002\u6587\u66f8\u5316\u3055\u308c\u305f\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u30fb\u30a6\u30a3\u30f3\u30c9\u30a6\u3068\u660e\u78ba\u306a\u30ed\u30fc\u30eb\u30d0\u30c3\u30af\u30fb\u30d1\u30b9\u306f\u3001\u4e0d\u6109\u5feb\u306a\u30b5\u30d7\u30e9\u30a4\u30ba\u3092\u907f\u3051\u308b\u3002.<\/p>\n\n<h2>\u5178\u578b\u7684\u306a\u30ed\u30b0\u30b7\u30b0\u30cd\u30c1\u30e3\u3092\u8a8d\u8b58\u3059\u308b<\/h2>\n\n<p>\u3088\u304f\u3042\u308b\u30d1\u30bf\u30fc\u30f3\u3092\u77e5\u3063\u3066\u3044\u308c\u3070\u3001\u30ed\u30b0\u304b\u3089rDNS\u306e\u554f\u984c\u3092\u3059\u3050\u306b\u8a8d\u8b58\u3067\u304d\u307e\u3059\u3002Postfix\u306e\u5834\u5408\u3001\u201ewarning: hostname ... verification failed\u201c\u3001\u201eHolo command rejected: need fully-qualified hostname\u201c\u3001\u201eClient host rejected: cannot find your reverse hostname \u201c\u3068\u3044\u3063\u305f\u30e1\u30c3\u30bb\u30fc\u30b8\u306f\u30ae\u30e3\u30c3\u30d7\u3092\u793a\u3057\u3066\u3044\u308b\u3002\u4f8b\u3048\u3070\u3001Exim\u306f \u201eHelo name contains a non-existent domain \u201c\u3084 \u201ereverse DNS lookup failure \u201c\u3068\u5831\u544a\u3057\u307e\u3059\u3002\u79c1\u306f\u3053\u306e\u3088\u3046\u306a\u30a4\u30d9\u30f3\u30c8\u3092\u30ec\u30fc\u30c8\u5236\u9650\u3084greylisting\u3068\u95a2\u9023\u4ed8\u3051\u3066\u3044\u307e\u3059\u3002\u306a\u305c\u306a\u3089\u3001PTR\u304c\u898b\u3064\u304b\u3089\u306a\u3044\u3068\u30d5\u30a9\u30ed\u30fc\u30a2\u30c3\u30d7\u30c1\u30a7\u30c3\u30af\u304c\u9023\u9396\u7684\u306b\u884c\u308f\u308c\u3001\u63a5\u7d9a\u304c\u3055\u3089\u306b\u9045\u304f\u306a\u308b\u3053\u3068\u304c\u3088\u304f\u3042\u308b\u304b\u3089\u3067\u3059\u3002.<\/p>\n\n<h2>\u97f3\u91cf\u8abf\u6574\u3068IP\u30a6\u30a9\u30fc\u30e0\u30a2\u30c3\u30d7<\/h2>\n\n<p>\u65b0\u3057\u3044IP\u306f\u614e\u91cd\u306b\u59cb\u3081\u307e\u3059\u30021\u65e5\u306e\u9001\u4fe1\u91cf\u3092\u5f90\u3005\u306b\u5897\u3084\u3057\u3001\u30d0\u30a6\u30f3\u30b9\u7387\u3068\u30af\u30ec\u30fc\u30e0\u7387\u3092\u4f4e\u304f\u4fdd\u3063\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u3067\u3059\u3050\u306b <strong>\u30af\u30ea\u30fc\u30f3\u30d2\u30b9\u30c8\u30ea\u30fc<\/strong>, rDNS\u3068\u8a8d\u8a3c\u306b\u56f2\u307e\u308c\u3066\u3044\u308b\u3002\u6700\u521d\u306e\u3046\u3061\u306f\u3001\u6709\u52b9\u3067\u30a2\u30af\u30c6\u30a3\u30d6\u306a\u53d7\u4fe1\u8005\u306e\u307f\u3092\u30bf\u30fc\u30b2\u30c3\u30c8\u306b\u6df7\u305c\u3001\u30de\u30fc\u30b1\u30c6\u30a3\u30f3\u30b0\u30e1\u30fc\u30eb\u3068\u30c8\u30e9\u30f3\u30b6\u30af\u30b7\u30e7\u30f3\u30e1\u30fc\u30eb\u3092\u5206\u3051\u3001\u30bd\u30d5\u30c8\u30d0\u30a6\u30f3\u30b9\u306b\u306f\u30ea\u30d4\u30fc\u30c8\u306e\u5d50\u3067\u306f\u306a\u304f\u30b9\u30ed\u30c3\u30c8\u30ea\u30f3\u30b0\u3067\u5bfe\u5fdc\u3057\u307e\u3057\u305f\u3002\u4e00\u8cab\u6027\u306f\u30b9\u30d1\u30a4\u30af\u306b\u52dd\u308b\uff1a\u4e00\u8cab\u3057\u305f\u8ca0\u8377\u3001\u4e88\u6e2c\u53ef\u80fd\u306a\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u30d1\u30bf\u30fc\u30f3\u3001\u5b89\u5b9a\u3057\u305frDNS\/MTA\u30b7\u30b0\u30ca\u30eb\u306f\u3001\u8a55\u5224\u3068\u53d7\u4fe1\u7bb1\u306e\u914d\u7f6e\u3068\u3044\u3046\u70b9\u3067\u76f4\u63a5\u7684\u306a\u914d\u5f53\u3092\u3082\u305f\u3089\u3057\u307e\u3059\u3002.<\/p>\n\n<h2>\u30cd\u30fc\u30df\u30f3\u30b0\u30b9\u30ad\u30fc\u30e0\u3068\u500b\u5225\u306e\u30c7\u30a3\u30b9\u30d1\u30c3\u30c1\u30d1\u30b9<\/h2>\n\n<p>\u539f\u56e0\u3092\u7d5e\u308a\u8fbc\u3080\u305f\u3081\u306b\u3001\u79c1\u306f\u6280\u8853\u7684\u306b\u3001\u307e\u305f\u540d\u524d\u3067\u30d1\u30b9\u3092\u5206\u3051\u3066\u3044\u308b\u3002\u305f\u3068\u3048\u3070\u3001Transactional\u306ftxn.mail.example.com\u3001Marketing\u306fmktg.mail.example.com\u3092\u53d6\u5f97\u3059\u308b\u3002\u305d\u308c\u305e\u308c\u72ec\u81ea\u306eIP\u3068\u72ec\u81ea\u306ePTR\u3092\u6301\u3064\u3002\u3053\u308c\u306b\u3088\u308a\u3001rDNS\u306e\u5909\u66f4\u3068\u30dc\u30ea\u30e5\u30fc\u30e0\u30eb\u30fc\u30eb\u3092\u3001\u3059\u3079\u3066\u3092\u6df7\u5728\u3055\u305b\u308b\u3053\u3068\u306a\u304f\u30c1\u30e3\u30cd\u30eb\u3054\u3068\u306b\u5236\u5fa1\u3067\u304d\u307e\u3059\u3002EHLO\u540d\u306f\u5e38\u306bPTR\u5b9b\u5148\u306b\u5bfe\u5fdc\u3057\u3001\u8a3c\u660e\u66f8\u306f\u3053\u306eFQDN\u3092\u30ab\u30d0\u30fc\u3059\u308b\u3002\u79c1\u306f\u3001\u6a5f\u80fd\u306e\u306a\u3044\u96c6\u5408\u540d\uff08\u201esmtp\u201c\u3001\u201eserver\u201c\uff09\u306f\u907f\u3051\u3001\u660e\u78ba\u306a\u5f79\u5272\u3068\u6c34\u5e73\u65b9\u5411\u306e\u30b9\u30b1\u30fc\u30eb\u30a2\u30a6\u30c8\u306e\u305f\u3081\u306e\u9023\u7d9a\u756a\u53f7\uff08mailout-1\u3001mailout-2 ...\uff09\u3092\u597d\u3080\u3002.<\/p>\n\n<h2>\u898b\u843d\u3068\u3057\u304c\u3061\u306a\u30a8\u30c3\u30b8\u30b1\u30fc\u30b9<\/h2>\n\n<ul>\n  <li>\u3064\u306eIP\u306b\u8907\u6570\u306ePTR\u3092\u8a2d\u5b9a\u3059\u308b\u3068\u3001FCRDNS\u304c\u96e3\u3057\u304f\u306a\u308a\u307e\u3059\u3002 <strong>a<\/strong>.<\/li>\n  <li>\u8907\u6570\u306eA\/AAA\u30ec\u30b3\u30fc\u30c9\u3092\u6301\u3064EHLO\u30db\u30b9\u30c8\u540d\u306f\u3001\u4ee5\u4e0b\u306e\u9650\u308aOK\u3067\u3059\u3002 <strong>\u9001\u4fe1IP<\/strong> \u304c\u305d\u306e\u4e2d\u306b\u3044\u308b\u3002.<\/li>\n  <li>IPv6\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u304c\u6a5f\u80fd\u3057\u3066\u3044\u306a\u3044\u65e2\u5b58\u306eAAAA\u30ec\u30b3\u30fc\u30c9\u306f\u30bf\u30a4\u30e0\u30a2\u30a6\u30c8\u306b\u3064\u306a\u304c\u308b\u3002.<\/li>\n  <li>\u30db\u30b9\u30c8\u540d\u306e\u30a2\u30f3\u30c0\u30fc\u30b9\u30b3\u30a2\u306fHELO\u306e\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u3092\u7834\u308a\u307e\u3059\u3002.<\/li>\n  <li>\u30af\u30e9\u30a6\u30c9IP\u306e\u5207\u308a\u66ff\u3048\uff1a\u56fa\u5b9a\u30a2\u30c9\u30ec\u30b9\u306e\u78ba\u4fdd\u3068rDNS\u306e\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u306f\u3001\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u5207\u308a\u66ff\u3048\u306e\u5f8c\u3067\u306f\u306a\u304f\u3001\u305d\u306e\u524d\u306b\u884c\u3044\u307e\u3059\u3002.<\/li>\n<\/ul>\n\n<h2>\u5b9f\u8df5\u304b\u3089\u306e\u9ad8\u5ea6\u306a\u30c6\u30b9\u30c8<\/h2>\n\n<p>dig\u306b\u52a0\u3048\u3001host\u3001drill\u3001nslookup\u3092\u30af\u30ed\u30b9\u30c1\u30a7\u30c3\u30af\u306b\u4f7f\u3046\u306e\u304c\u597d\u304d\u3060\u3002swaks\u3084\u5358\u7d14\u306aOpenSSL\u30cf\u30f3\u30c9\u30b7\u30a7\u30a4\u30af\u3092\u4f7f\u3048\u3070\u3001MTA\u304c\u5b9f\u969b\u306b\u3069\u306eEHLO\u3092\u9001\u4fe1\u3057\u3066\u3044\u308b\u306e\u304b\u3001\u3069\u306e\u8a3c\u660e\u66f8\u304c\u63d0\u793a\u3055\u308c\u3066\u3044\u308b\u306e\u304b\u3092\u78ba\u8a8d\u3067\u304d\u308b\u3002IPv4\u3068IPv6\u3092\u5225\u3005\u306b\u30c6\u30b9\u30c8\u3057\u3001\u7279\u306b\u5e0c\u671b\u306e\u30d5\u30a1\u30df\u30ea\u30fc\u3092\u5f37\u5236\u3059\u308b\u3053\u3068\u3067\u3001\u77db\u76fe\u3092\u7d20\u65e9\u304f\u898b\u3064\u3051\u308b\u3002\u3055\u3089\u306b\u3001Received\u30d8\u30c3\u30c0\u30fc\u30921\u5bfe1\u3067\u8a55\u4fa1\u3057\u3001\u76ee\u306b\u898b\u3048\u308b\u30d1\u30b9\u304c\u79c1\u306e\u8a08\u753b\u3057\u305f\u30a4\u30f3\u30d5\u30e9\u3068\u30cd\u30fc\u30df\u30f3\u30b0\u30b3\u30f3\u30bb\u30d7\u30c8\u306b\u5408\u3063\u3066\u3044\u308b\u304b\u3069\u3046\u304b\u3092\u78ba\u8a8d\u3059\u308b\u3002.<\/p>\n\n<h2>IPv6\u306e\u8a73\u7d30\uff1a\u30cb\u30d6\u30eb\u8868\u8a18\u3068\u30a2\u30c9\u30ec\u30b9\u9078\u629e<\/h2>\n\n<p>IPv6\u306e\u5834\u5408\u306f\u3001PTR\u3092 <strong>\u304a\u3064\u307e\u307f<\/strong> (\u900616\u9032\u6570\u306b\u30c9\u30c3\u30c8)\u3002\u305d\u3046\u3057\u306a\u3044\u3068ip6.arpa\u3092\u304d\u308c\u3044\u306b\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3067\u304d\u306a\u3044\u304b\u3089\u3060\u3002\u305d\u3046\u3057\u306a\u3044\u3068ip6.arpa\u3092\u304d\u308c\u3044\u306b\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3067\u304d\u306a\u3044\u304b\u3089\u3060\u3002\u79c1\u306f\u6574\u9813\u3059\u308b\uff1a\u30e9\u30f3\u30c0\u30e0\u306b\u751f\u6210\u3055\u308c\u305f\u30a2\u30c9\u30ec\u30b9\u306e\u6df7\u5728\u306f\u907f\u3051\u3001\u8907\u6570\u306ePTR\u306f\u4f7f\u308f\u305a\u3001\u8ee2\u9001\u30eb\u30c3\u30af\u30a2\u30c3\u30d7\u306f\u30b5\u30fc\u30d0\u30fc\u304c\u5b9f\u969b\u306b\u30e1\u30fc\u30ea\u30f3\u30b0\u3057\u3066\u3044\u308b\u5834\u6240\u3067\u306e\u307f\u884c\u3046\u3002\u3053\u3046\u3059\u308b\u3053\u3068\u3067\u3001FCRDNS\u306e\u30c1\u30a7\u30c3\u30af\u3067\u30dd\u30a4\u30f3\u30c8\u3092\u5931\u3046\u3053\u3068\u306f\u3042\u308a\u307e\u305b\u3093\u3002.<\/p>\n\n<h2>\u30b9\u30de\u30fc\u30b3\u30b9\u30c8\u3068\u8cac\u4efb\u5171\u6709<\/h2>\n\n<p>\u5916\u90e8\u306e\u30b9\u30de\u30fc\u30c8\u30db\u30b9\u30c8\u3092\u4f7f\u3046\u5834\u5408\u3001\u305d\u306erDNS\u304c\u6c7a\u5b9a\u7684\u3067\u3059\u3002\u79c1\u306f\u3001\u81ea\u5206\u306eEHLO\u304c\u53d7\u4fe1\u8005\u306e\u305f\u3081\u306b\u30b9\u30de\u30fc\u30c8\u30db\u30b9\u30c8\u306e\u3082\u306e\u3068\u300c\u885d\u7a81\u300d\u3057\u306a\u3044\u3088\u3046\u306b\u3057\u307e\u3059\u3002\u30ea\u30ec\u30fc\u306b\u3088\u3063\u3066\u306f\u3001HELO\u540d\u3092\u4e0a\u66f8\u304d\u3057\u305f\u308a\u3001\u4e2d\u7acb\u7684\u306a\u30d0\u30ca\u30fc\u3092\u8a2d\u5b9a\u3059\u308b\u3082\u306e\u3082\u3042\u308a\u307e\u3059\u304c\u3001\u79c1\u306f\u30b9\u30de\u30fc\u30c8\u30db\u30b9\u30c8\u306ePTR\u3001\u8a3c\u660e\u66f8\u3001\u8a55\u5224\u304c\u6b63\u3057\u3044\u9650\u308a\u3001\u3053\u308c\u306b\u8010\u3048\u3066\u3044\u307e\u3059\u3002\u79c1\u306f\u5951\u7d04\u4e0a\u3001rDNS\u306e\u30ab\u30b9\u30bf\u30de\u30a4\u30ba\u3084IP\u306e\u56fa\u5b9a\u5316\u304c\u53ef\u80fd\u3067\u3042\u308a\u3001\u79d8\u5bc6\u88cf\u306b\u30ed\u30fc\u30c6\u30fc\u30b7\u30e7\u30f3\u3084\u5171\u6709\u304c\u884c\u308f\u308c\u3066\u3044\u306a\u3044\u3053\u3068\u3092\u78ba\u8a8d\u3057\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n<h2>\u904b\u8ee2\u4e2d\u306e\u30a8\u30e9\u30fc\u30d1\u30bf\u30fc\u30f3\u306e\u69cb\u9020\u5316\u3055\u308c\u305f\u5206\u985e<\/h2>\n\n<p>rDNS\u306e\u554f\u984c\u306f\u30014.7.x\u307e\u305f\u306f5.7.x\u30b3\u30fc\u30c9\u3068\u3057\u3066\u8868\u793a\u3055\u308c\u3001\u591a\u304f\u306e\u5834\u5408\u3001\u300cReverse DNS required\u300d\u307e\u305f\u306f\u300cSPF\/DKIM alignment fail\u300d\u3092\u53c2\u7167\u3057\u3066\u3044\u307e\u3059\u3002\u79c1\u306f\u30b5\u30fc\u30d0\u30fc\u306e\u30c6\u30ad\u30b9\u30c8\u3092\u6587\u5b57\u901a\u308a\u8aad\u307f\u307e\u3059\uff1a\u300c\u30d0\u30ca\u30fc\u306e\u4e0d\u4e00\u81f4\u300d\u3068\u66f8\u3044\u3066\u3042\u308c\u3070\u3001EHLO\u3092\u51e6\u7406\u3057\u3001\u300cPTR\u306a\u3057\u300d\u3068\u66f8\u3044\u3066\u3042\u308c\u3070\u3001\u30d7\u30ed\u30d0\u30a4\u30c0\u30fc\u306e\u30b1\u30fc\u30b9\u3092\u51e6\u7406\u3057\u307e\u3059\u3002rDNS\u3001\u30d0\u30ca\u30fc\u3001FCRDNS\u304c\u9593\u9055\u3044\u306a\u304f\u4e00\u81f4\u3057\u305f\u5834\u5408\u306e\u307f\u3001\u30b3\u30f3\u30c6\u30f3\u30c4\u3001\u30ec\u30d4\u30e5\u30c6\u30fc\u30b7\u30e7\u30f3\u3001\u30dc\u30ea\u30e5\u30fc\u30e0\u306e\u7d30\u304b\u3044\u6700\u9069\u5316\u306b\u79fb\u308b\u3002.<\/p>\n\n<h2>\u30af\u30e9\u30a6\u30c9\u74b0\u5883\u3067\u306e\u904b\u7528<\/h2>\n\n<p>\u591a\u304f\u306e\u30af\u30e9\u30a6\u30c9\u3067\u306f\u3001rDNS\u306e\u305f\u3081\u306b\u500b\u5225\u306e\u30ea\u30af\u30a8\u30b9\u30c8\u3084API\u30b3\u30fc\u30eb\u3092\u5fc5\u8981\u3068\u3059\u308b\u3002\u305d\u306e\u305f\u3081\u3001\u79c1\u306f\u56fa\u5b9a\uff08\u4e88\u7d04\uff09\u30a2\u30c9\u30ec\u30b9\u3067\u4f5c\u696d\u3057\u3001IaC\u30ef\u30fc\u30af\u30d5\u30ed\u30fc\u3067rDNS\u540d\u3092\u6587\u66f8\u5316\u3057\u307e\u3059\u3002\u79c1\u306f\u3001\u30a8\u30d5\u30a7\u30e1\u30e9\u30eb\u306aIP\u3084\u3001\u9001\u4fe1\u30e1\u30fc\u30eb\u30d1\u30b9\u3067IP\u3092\u56fa\u5b9a\u3057\u306a\u3044\u30aa\u30fc\u30c8\u30b9\u30b1\u30fc\u30ea\u30f3\u30b0\u3092\u907f\u3051\u3066\u3044\u308b\u3002\u5909\u66f4\u304c\u4fdd\u7559\u3055\u308c\u3066\u3044\u308b\u5834\u5408\u306f\u3001\u307e\u305aPTR\u3068\u30d5\u30a9\u30ef\u30fc\u30c9\u3092\u30aa\u30fc\u30b1\u30b9\u30c8\u30ec\u30fc\u30b7\u30e7\u30f3\u3057\u3001TTL\u3092\u5f85\u3061\u3001\u5236\u5fa1\u3055\u308c\u305f\u65b9\u6cd5\u3067\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u3092\u79fb\u52d5\u3055\u305b\u307e\u3059\u3002.<\/p>\n\n<h2>\u7c21\u5358\u306b\u307e\u3068\u3081\u308b\u3068<\/h2>\n\n<p>\u78ba\u5b9f\u306b\u9001\u4fe1\u3057\u305f\u3044\u306e\u3067\u3042\u308c\u3070\u3001\u307e\u305a\u4e00\u610f\u306ePTR\u3092\u4f5c\u6210\u3057\u3001\u9069\u5207\u306a <strong>\u30a4\u30fc\u30a8\u30eb\u30aa\u30fc<\/strong> \u30bb\u30ad\u30e5\u30a2\u3067\u3042\u308b\u3002\u305d\u306e\u5f8c\u306eFCRDNS\u30c1\u30a7\u30c3\u30af\u3068\u4e00\u8cab\u3057\u305f\u30d5\u30a9\u30ef\u30fc\u30c9\u30eb\u30c3\u30af\u30a2\u30c3\u30d7\u306f\u3001\u30b5\u30fc\u30d0\u30fc\u306e\u8eab\u5143\u3092\u78ba\u8a8d\u3057\u307e\u3059\u3002SPF\u3001DKIM\u3001DMARC\u306f\u3001\u753b\u50cf\u3092\u5b8c\u6210\u3055\u305b\u3001\u30d5\u30a3\u30eb\u30bf\u304c\u4fe1\u983c\u3067\u304d\u308b\u9001\u4fe1\u8005\u3092\u6b63\u3057\u304f\u5206\u985e\u3059\u308b\u306e\u306b\u5f79\u7acb\u3061\u307e\u3059\u3002\u660e\u78ba\u306a\u540d\u524d\u3001\u56fa\u5b9aIP\u3001\u5b9a\u671f\u7684\u306a\u30c6\u30b9\u30c8\u306b\u3088\u308a\u3001\u79c1\u306f\u30ec\u30d4\u30e5\u30c6\u30fc\u30b7\u30e7\u30f3\u3092\u30b0\u30ea\u30fc\u30f3\u30be\u30fc\u30f3\u306b\u4fdd\u3063\u3066\u3044\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u30e1\u30c3\u30bb\u30fc\u30b8\u306f\u78ba\u5b9f\u306b\u53d7\u4fe1\u30c8\u30ec\u30a4\u306b\u5c4a\u304d\u3001\u624b\u4f5c\u696d\u306b\u3088\u308b\u624b\u76f4\u3057\u306b\u3088\u308b\u9ad8\u4fa1\u306a\u56de\u308a\u9053\u306f\u306a\u304f\u306a\u308a\u307e\u3059\u3002.<\/p>\n\n\n<figure class=\"wp-block-image size-full is-resized\">\n  <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/webhosting.de\/wp-content\/uploads\/2026\/03\/serverraum-hosting-4132.png\" alt=\"\" width=\"1536\" height=\"1024\"\/>\n<\/figure>","protected":false},"excerpt":{"rendered":"<p>\u30ea\u30d0\u30fc\u30b9DNS\u30e1\u30fc\u30eb\u30b7\u30b9\u30c6\u30e0\u3068PTR\u30ec\u30b3\u30fc\u30c9\u30db\u30b9\u30c6\u30a3\u30f3\u30b0\u306f\u30e1\u30fc\u30eb\u30b5\u30fc\u30d0\u30fc\u306e\u8a55\u4fa1\u306b\u4e0d\u53ef\u6b20\u3067\u3059\u3002\u30e1\u30fc\u30eb\u30a4\u30f3\u30d5\u30e9\u3092\u6700\u9069\u5316\u3059\u308b\u305f\u3081\u306e\u5b8c\u5168\u30ac\u30a4\u30c9.<\/p>","protected":false},"author":1,"featured_media":18562,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_crdt_document":"","inline_featured_image":false,"footnotes":""},"categories":[708],"tags":[],"class_list":["post-18569","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-email"],"acf":[],"_wp_attached_file":null,"_wp_attachment_metadata":null,"litespeed-optimize-size":null,"litespeed-optimize-set":null,"_elementor_source_image_hash":null,"_wp_attachment_image_alt":null,"stockpack_author_name":null,"stockpack_author_url":null,"stockpack_provider":null,"stockpack_image_url":null,"stockpack_license":null,"stockpack_license_url":null,"stockpack_modification":null,"color":null,"original_id":null,"original_url":null,"original_link":null,"unsplash_location":null,"unsplash_sponsor":null,"unsplash_exif":null,"unsplash_attachment_metadata":null,"_elementor_is_screenshot":null,"surfer_file_name":null,"surfer_file_original_url":null,"envato_tk_source_kit":null,"envato_tk_source_index":null,"envato_tk_manifest":null,"envato_tk_folder_name":null,"envato_tk_builder":null,"envato_elements_download_event":null,"_menu_item_type":null,"_menu_item_menu_item_parent":null,"_menu_item_object_id":null,"_menu_item_object":null,"_menu_item_target":null,"_menu_item_classes":null,"_menu_item_xfn":null,"_menu_item_url":null,"_trp_menu_languages":null,"rank_math_primary_category":null,"rank_math_title":null,"inline_featured_image":null,"_yoast_wpseo_primary_category":null,"rank_math_schema_blogposting":null,"rank_math_schema_videoobject":null,"_oembed_049c719bc4a9f89deaead66a7da9fddc":null,"_oembed_time_049c719bc4a9f89deaead66a7da9fddc":null,"_yoast_wpseo_focuskw":null,"_yoast_wpseo_linkdex":null,"_oembed_27e3473bf8bec795fbeb3a9d38489348":null,"_oembed_c3b0f6959478faf92a1f343d8f96b19e":null,"_trp_translated_slug_en_us":null,"_wp_desired_post_slug":null,"_yoast_wpseo_title":null,"tldname":null,"tldpreis":null,"tldrubrik":null,"tldpolicylink":null,"tldsize":null,"tldregistrierungsdauer":null,"tldtransfer":null,"tldwhoisprivacy":null,"tldregistrarchange":null,"tldregistrantchange":null,"tldwhoisupdate":null,"tldnameserverupdate":null,"tlddeletesofort":null,"tlddeleteexpire":null,"tldumlaute":null,"tldrestore":null,"tldsubcategory":null,"tldbildname":null,"tldbildurl":null,"tldclean":null,"tldcategory":null,"tldpolicy":null,"tldbesonderheiten":null,"tld_bedeutung":null,"_oembed_d167040d816d8f94c072940c8009f5f8":null,"_oembed_b0a0fa59ef14f8870da2c63f2027d064":null,"_oembed_4792fa4dfb2a8f09ab950a73b7f313ba":null,"_oembed_33ceb1fe54a8ab775d9410abf699878d":null,"_oembed_fd7014d14d919b45ec004937c0db9335":null,"_oembed_21a029d076783ec3e8042698c351bd7e":null,"_oembed_be5ea8a0c7b18e658f08cc571a909452":null,"_oembed_a9ca7a298b19f9b48ec5914e010294d2":null,"_oembed_f8db6b27d08a2bb1f920e7647808899a":null,"_oembed_168ebde5096e77d8a89326519af9e022":null,"_oembed_cdb76f1b345b42743edfe25481b6f98f":null,"_oembed_87b0613611ae54e86e8864265404b0a1":null,"_oembed_27aa0e5cf3f1bb4bc416a4641a5ac273":null,"_oembed_time_27aa0e5cf3f1bb4bc416a4641a5ac273":null,"_tldname":null,"_tldclean":null,"_tldpreis":null,"_tldcategory":null,"_tldsubcategory":null,"_tldpolicy":null,"_tldpolicylink":null,"_tldsize":null,"_tldregistrierungsdauer":null,"_tldtransfer":null,"_tldwhoisprivacy":null,"_tldregistrarchange":null,"_tldregistrantchange":null,"_tldwhoisupdate":null,"_tldnameserverupdate":null,"_tlddeletesofort":null,"_tlddeleteexpire":null,"_tldumlaute":null,"_tldrestore":null,"_tldbildname":null,"_tldbildurl":null,"_tld_bedeutung":null,"_tldbesonderheiten":null,"_oembed_ad96e4112edb9f8ffa35731d4098bc6b":null,"_oembed_8357e2b8a2575c74ed5978f262a10126":null,"_oembed_3d5fea5103dd0d22ec5d6a33eff7f863":null,"_eael_widget_elements":null,"_oembed_0d8a206f09633e3d62b95a15a4dd0487":null,"_oembed_time_0d8a206f09633e3d62b95a15a4dd0487":null,"_aioseo_description":null,"_eb_attr":null,"_eb_data_table":null,"_oembed_819a879e7da16dd629cfd15a97334c8a":null,"_oembed_time_819a879e7da16dd629cfd15a97334c8a":null,"_acf_changed":null,"_wpcode_auto_insert":null,"_edit_last":null,"_edit_lock":null,"_oembed_e7b913c6c84084ed9702cb4feb012ddd":null,"_oembed_bfde9e10f59a17b85fc8917fa7edf782":null,"_oembed_time_bfde9e10f59a17b85fc8917fa7edf782":null,"_oembed_03514b67990db061d7c4672de26dc514":null,"_oembed_time_03514b67990db061d7c4672de26dc514":null,"rank_math_news_sitemap_robots":null,"rank_math_robots":null,"_eael_post_view_count":"609","_trp_automatically_translated_slug_ru_ru":null,"_trp_automatically_translated_slug_et":null,"_trp_automatically_translated_slug_lv":null,"_trp_automatically_translated_slug_fr_fr":null,"_trp_automatically_translated_slug_en_us":null,"_wp_old_slug":null,"_trp_automatically_translated_slug_da_dk":null,"_trp_automatically_translated_slug_pl_pl":null,"_trp_automatically_translated_slug_es_es":null,"_trp_automatically_translated_slug_hu_hu":null,"_trp_automatically_translated_slug_fi":null,"_trp_automatically_translated_slug_ja":null,"_trp_automatically_translated_slug_lt_lt":null,"_elementor_edit_mode":null,"_elementor_template_type":null,"_elementor_version":null,"_elementor_pro_version":null,"_wp_page_template":null,"_elementor_page_settings":null,"_elementor_data":null,"_elementor_css":null,"_elementor_conditions":null,"_happyaddons_elements_cache":null,"_oembed_75446120c39305f0da0ccd147f6de9cb":null,"_oembed_time_75446120c39305f0da0ccd147f6de9cb":null,"_oembed_3efb2c3e76a18143e7207993a2a6939a":null,"_oembed_time_3efb2c3e76a18143e7207993a2a6939a":null,"_oembed_59808117857ddf57e478a31d79f76e4d":null,"_oembed_time_59808117857ddf57e478a31d79f76e4d":null,"_oembed_965c5b49aa8d22ce37dfb3bde0268600":null,"_oembed_time_965c5b49aa8d22ce37dfb3bde0268600":null,"_oembed_81002f7ee3604f645db4ebcfd1912acf":null,"_oembed_time_81002f7ee3604f645db4ebcfd1912acf":null,"_elementor_screenshot":null,"_oembed_7ea3429961cf98fa85da9747683af827":null,"_oembed_time_7ea3429961cf98fa85da9747683af827":null,"_elementor_controls_usage":null,"_elementor_page_assets":[],"_elementor_screenshot_failed":null,"theplus_transient_widgets":null,"_eael_custom_js":null,"_wp_old_date":null,"_trp_automatically_translated_slug_it_it":null,"_trp_automatically_translated_slug_pt_pt":null,"_trp_automatically_translated_slug_zh_cn":null,"_trp_automatically_translated_slug_nl_nl":null,"_trp_automatically_translated_slug_pt_br":null,"_trp_automatically_translated_slug_sv_se":null,"rank_math_analytic_object_id":null,"rank_math_internal_links_processed":"1","_trp_automatically_translated_slug_ro_ro":null,"_trp_automatically_translated_slug_sk_sk":null,"_trp_automatically_translated_slug_bg_bg":null,"_trp_automatically_translated_slug_sl_si":null,"litespeed_vpi_list":null,"litespeed_vpi_list_mobile":null,"rank_math_seo_score":null,"rank_math_contentai_score":null,"ilj_limitincominglinks":null,"ilj_maxincominglinks":null,"ilj_limitoutgoinglinks":null,"ilj_maxoutgoinglinks":null,"ilj_limitlinksperparagraph":null,"ilj_linksperparagraph":null,"ilj_blacklistdefinition":null,"ilj_linkdefinition":null,"_eb_reusable_block_ids":null,"rank_math_focus_keyword":"Reverse DNS Mail-Hosting","rank_math_og_content_image":null,"_yoast_wpseo_metadesc":null,"_yoast_wpseo_content_score":null,"_yoast_wpseo_focuskeywords":null,"_yoast_wpseo_keywordsynonyms":null,"_yoast_wpseo_estimated-reading-time-minutes":null,"rank_math_description":null,"surfer_last_post_update":null,"surfer_last_post_update_direction":null,"surfer_keywords":null,"surfer_location":null,"surfer_draft_id":null,"surfer_permalink_hash":null,"surfer_scrape_ready":null,"_thumbnail_id":"18562","footnotes":null,"_links":{"self":[{"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/posts\/18569","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/comments?post=18569"}],"version-history":[{"count":0,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/posts\/18569\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/media\/18562"}],"wp:attachment":[{"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/media?parent=18569"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/categories?post=18569"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/webhosting.de\/ja\/wp-json\/wp\/v2\/tags?post=18569"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}