![\"\u30dd\u30fc\u30c8465\u3068587\u306e\u9055\u3044\u3068\u306f\uff1f\"](\"https:\/\/sendgrid.kke.co.jp\/blog\/wp\/wp-content\/uploads\/2022\/11\/20221122_blog.png\")
<\/p>\n<\/p>\n
\n\u3053\u306e\u8a18\u4e8b\u306f What\u2019s the Difference Between Ports 465 and 587?<\/a> \u306e\u6284\u8a33\u3067\u3059\u3002<\/p>\n<\/blockquote>\n
\u30e1\u30fc\u30eb\u9001\u4fe1\u8005\u306e\u7686\u3055\u3093\u304b\u3089\u3001\u30dd\u30fc\u30c8465\u3068587\u306e\u9055\u3044\u306b\u3064\u3044\u3066\u3088\u304f\u805e\u304b\u308c\u307e\u3059\u3002\u3053\u306e\u8cea\u554f\u306b\u6b63\u78ba\u306b\u7b54\u3048\u308b\u305f\u3081\u306b\u306f\u3001\u5c11\u3057\u80cc\u666f\u306e\u60c5\u5831\u3092\u3054\u8aac\u660e\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
SMTP\u3068\u306f? <\/h3>\n
SMTP\u306fSimple Mail Transfer Protocol\u306e\u7565\u3067\u3001\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u7d4c\u7531\u3067\u30e1\u30fc\u30eb\u3092\u9001\u4fe1\u3059\u308b\u300c\u65b9\u6cd5\u300d\u3092\u610f\u5473\u3057\u307e\u3059\u30021982\u5e748\u6708\u306bRFC 821<\/a>\u3067\u6700\u521d\u306b\u6a19\u6e96\u5316\u3055\u308c\u307e\u3057\u305f\u3002\u8a73\u7d30\u306b\u3064\u3044\u3066\u306f\u3001\u3053\u3061\u3089<\/a>\u306e\u30d6\u30ed\u30b0\u3092\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n
\u30dd\u30fc\u30c8\u3068\u30b5\u30fc\u30d3\u30b9\u306f\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u3067\u3069\u306e\u3088\u3046\u306b\u7ba1\u7406\u3055\u308c\u307e\u3059\u304b\uff1f<\/h3>\n
\u7279\u5b9a\u306e\u30c6\u30af\u30ce\u30ed\u30b8\u30fc\u306b\u95a2\u9023\u3059\u308b\u756a\u53f7\u306e\u5272\u308a\u5f53\u3066\u3092\u7ba1\u7406\u3059\u308b2\u3064\u306e\u7d71\u6cbb\u6a5f\u95a2\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n
1\u3064\u76ee\u306e \u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u5272\u5f53\u756a\u53f7\u516c\u793e\uff08IANA<\/a>\uff09\u306f\u3001\u30c9\u30e1\u30a4\u30f3\u540d\u3001\u756a\u53f7\u30ea\u30bd\u30fc\u30b9\u3001\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u5272\u308a\u5f53\u3066\u3001\u3068\u3044\u3046\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u306b\u95a2\u9023\u3059\u308b3\u3064\u306e\u4e3b\u8981\u306a\u8981\u7d20\u3092\u7d71\u62ec\u3057\u3066\u3044\u308b\u6a5f\u95a2\u3067\u3059\u3002\u307e\u305f\u3001\u6628\u4eca\u7279\u306b\u91cd\u8981\u306b\u306a\u3063\u3066\u3044\u308b\u3001\u30b5\u30fc\u30d3\u30b9\u306e\u30d7\u30ed\u30c8\u30b3\u30eb\u3068\u30dd\u30fc\u30c8\u306e\u5bfe\u5fdc\u30ea\u30b9\u30c8\u3082\u7ba1\u7406\u3057\u3066\u3044\u307e\u3059\u3002\u30dd\u30fc\u30c8\u304c\u7a7a\u3044\u3066\u3044\u308b\u9650\u308a\u3001\u8ab0\u3067\u3082\u65b0\u3057\u3044\u30b5\u30fc\u30d3\u30b9\u3092\u767b\u9332\u3067\u304d\u307e\u3059\u3002\u3057\u304b\u3057\u306a\u304c\u3089\u3001IANA\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u304b\u3089\u3068\u3044\u3063\u3066\u3001\u3053\u306e\u30dd\u30fc\u30c8\u3068\u306e\u9593\u306e\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u304c\u300c\u5584\u826f\u306a\u300d\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u3067\u3042\u308b\u3053\u3068\u304c\u4fdd\u8a3c\u3055\u308c\u3066\u3044\u308b\u308f\u3051\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
2\u3064\u76ee\u306e\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u6280\u8853\u7279\u5225\u8abf\u67fb\u59d4\u54e1\u4f1a\uff08IETF<\/a>\uff09\u306f\u3001\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u306e\u904b\u7528\u3092\u6539\u5584\u3059\u308b\u305f\u3081\u306b\u6a19\u6e96\u5316\u3092\u884c\u3063\u3066\u3044\u308b\u56e3\u4f53\u3067\u3059\u3002 IETF\u306fRFC\uff08Request for Comments\uff09\u3068\u3057\u3066\u3001\u5909\u66f4\u70b9\u3084\u6539\u5584\u70b9\u306e\u63d0\u6848\u3092\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u79c1\u305f\u3061\u306f\u3001\u30e1\u30fc\u30eb\u3068\u306e\u95a2\u4fc2\u304c\u6df1\u3044\u3001SMTP\u3084\u30dd\u30fc\u30c8465\u304a\u3088\u3073587\u306b\u95a2\u3059\u308bRFC\u306b\u7740\u76ee\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
TLS\u3084StartTLS\u3068\u306f\u4f55\u304b\uff1f<\/h3>\n
\u5c11\u3057\u5c02\u9580\u7684\u306a\u7528\u8a9e\u3067\u3042\u308b\u3001TLS\uff08Transport Layer Security\uff09\u3068StartTLS<\/a>\u306b\u3064\u3044\u3066\u3054\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n
TLS(\u6697\u9ed9\u7684TLS)\u306f\u3001\u521d\u671f\u63a5\u7d9a\u3067Secure Socket Layer\uff08SSL\uff09\u307e\u305f\u306fTransport Layer Security\uff08TLS\uff09\u8a3c\u660e\u66f8\u3092\u4f7f\u3063\u3066\u958b\u59cb\u3055\u308c\u307e\u3059\u3002\u30af\u30e9\u30a4\u30a2\u30f3\u30c8\u5074\u306b\u5c11\u3057\u591a\u304f\u306e\u4f5c\u696d\u3092\u8981\u6c42\u3059\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u304c\u3001\u63a5\u7d9a\u306f\u6700\u521d\u304b\u3089\u6697\u53f7\u5316\u3055\u308c\u307e\u3059\u3002<\/p>\n
StartTLS\u306f\u3001\u30d7\u30ec\u30fc\u30f3\u30c6\u30ad\u30b9\u30c8\u3067\u3084\u308a\u53d6\u308a\u3092\u958b\u59cb\u3057\u3001\u53ef\u80fd\u3067\u3042\u308c\u3070TLS\u306b\u30a2\u30c3\u30d7\u30b0\u30ec\u30fc\u30c9\u3059\u308b\u30d7\u30ed\u30c8\u30b3\u30eb\u30b3\u30de\u30f3\u30c9\u3067\u3059\u3002 1\u3064\u306e\u30dd\u30fc\u30c8\u3067\u30d7\u30ec\u30fc\u30f3\u30c6\u30ad\u30b9\u30c8\u3068TLS\u306e\u4e21\u65b9\u3092\u6271\u3046\u3053\u3068\u304c\u3067\u304d\u308b\u305f\u3081\u3001\u5229\u7528\u304c\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u30dd\u30fc\u30c8465: TLS\u30d7\u30ed\u30c8\u30b3\u30eb\u306b\u3088\u308b\u30e1\u30c3\u30bb\u30fc\u30b8\u9001\u4fe1\u3092\u884c\u3046\u30dd\u30fc\u30c8<\/h3>\n
\u30dd\u30fc\u30c8465\u3092\u6697\u9ed9\u7684TLS\u306e\u305f\u3081\u306b\u4f7f\u7528\u3059\u308b\u3053\u3068\u306f\u53ef\u80fd\u3067\u3059\u304c\u3001\u30dd\u30fc\u30c8587\u3068StartTLS\u306e\u5229\u7528\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\u3002<\/p>\n
\u30dd\u30fc\u30c8465\u306b\u306f\u8208\u5473\u6df1\u3044\u6b74\u53f2\u304c\u3042\u308a\u307e\u3059\u30021997\u5e74\u306e\u521d\u3081\u306b\u3001SMTP\u306b\u3088\u308b\u901a\u4fe1\u3092\u6697\u53f7\u5316\u3059\u308b\u65b0\u3057\u3044\u898f\u683c\u304c\u516c\u958b\u3055\u308c\u307e\u3057\u305f<\/a>\u3002\u305d\u308c\u306b\u4f34\u3044\u3001IANA\u306f\u30dd\u30fc\u30c8465\u3092smtps\u3078\u5272\u308a\u5f53\u3066\u307e\u3057\u305f\u3002 \u305f\u3060\u3057\u3001IANA\u306b\u3088\u3063\u3066\u306e\u307f\u767b\u9332\u3055\u308c\u3001IETF\u306b\u3088\u3063\u3066RFC\u306b\u306f\u767b\u9332\u3055\u308c\u306a\u304b\u3063\u305f\u305f\u3081\u3001SMTP\u306e\u6697\u53f7\u5316\u901a\u4fe1\u7528\u306e\u30dd\u30fc\u30c8\u3068\u3057\u3066\u5b8c\u5168\u306b\u306f\u8a8d\u3081\u3089\u308c\u307e\u305b\u3093\u3067\u3057\u305f\u3002\u540c\u5e74\u3001IETF\u306f\u30dd\u30fc\u30c8587\u306eStartTLS\u3092SMTP\u306e\u6697\u53f7\u5316\u30d7\u30ed\u30c8\u30b3\u30eb\u3068\u3057\u3066\u6a19\u6e96\u5316\u3057\u307e\u3057\u305f\u3002<\/p>\n
SMTP\u306e\u6697\u53f7\u5316\u30d7\u30ed\u30bb\u30b9\u3092\u7c21\u7565\u5316\u3059\u308b\u305f\u3081\u306b\u3001IANA\u306fsmtps\u3078\u306e\u30dd\u30fc\u30c8465\u306e\u5272\u308a\u5f53\u3066\u3092\u7121\u52b9\u5316\u3057\u307e\u3057\u305f\u3002\u3057\u304b\u3057\u3001\u30dd\u30fc\u30c8465\u3068\u6697\u9ed9\u7684TLS\u306f\u305d\u308c\u306a\u308a\u306b\u5e83\u307e\u3063\u3066\u3044\u305f\u305f\u3081\u3001\u304b\u306a\u308a\u306e\u6df7\u4e71\u3092\u62db\u304f\u3053\u3068\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u306e\u4e8b\u614b\u3092\u6539\u5584\u3059\u308b\u305f\u3081\u306b\u3001IETF\u306f\u3001TLS\u30d7\u30ed\u30c8\u30b3\u30eb\u3067\u306e\u901a\u4fe1\u306b\u518d\u3073\u30dd\u30fc\u30c8465\u3092\u5229\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u4fee\u6b63<\/a>\u3057\u307e\u3057\u305f\u3002<\/p>\n
\u4eca\u65e5\u3067\u306f\u3001\u30dd\u30fc\u30c8465\u306f\u3001\u30e1\u30c3\u30bb\u30fc\u30b8\u9001\u4fe1\u7528\u306e\u30b5\u30fc\u30d3\u30b9\u30dd\u30fc\u30c8\u3068SSM\u7528\u306eURL Rendezvous Directory(URD)\u3068\u3057\u3066\u3001IANA\u30ec\u30b8\u30b9\u30c8\u30ea<\/a>\u306b\u8a18\u8f09\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3057\u304b\u3057\u3001URD<\/a> \u306f SMTP \u3068\u306f\u4f55\u306e\u95a2\u4fc2\u3082\u306a\u3044\u306e\u3067\u3001\u30dd\u30fc\u30c8\u5468\u308a\u306e\u6df7\u4e71\u306b\u62cd\u8eca\u3092\u304b\u3051\u3066\u3057\u307e\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u30dd\u30fc\u30c8587: \u30e1\u30c3\u30bb\u30fc\u30b8\u9001\u4fe1\u3092\u884c\u3046\u30dd\u30fc\u30c8<\/h3>\n
\u30dd\u30fc\u30c8587\u306fSMTP\u3067\u30e1\u30c3\u30bb\u30fc\u30b8\u9001\u4fe1\u3092\u884c\u3046\u969b\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u30dd\u30fc\u30c8\u3067\u3059\u3002<\/p>\n
\u30dd\u30fc\u30c8465\u3068\u30dd\u30fc\u30c8587\u306e\u6df7\u8ff7\u306e\u6b74\u53f2\u306f\u3001\u6697\u53f7\u5316\u901a\u4fe1\u306e\u6a19\u6e96\u5316\u304c\u8b70\u8ad6\u3055\u308c\u3066\u3044\u305f1997\u5e74\u307e\u3067\u3055\u304b\u306e\u307c\u308a\u307e\u3059\u3002\u6700\u7d42\u7684\u306b\u306f\u3001\u5e73\u6587\u3067\u9001\u4fe1\u3057\u305f\u308a\u3001\u540c\u3058\u30dd\u30fc\u30c8\u3092\u4f7f\u7528\u3057\u3066 TLS \u306b\u30a2\u30c3\u30d7\u30b0\u30ec\u30fc\u30c9\u3057\u305f\u308a\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308bStartTLS \u304c\u9078\u3070\u308c\u307e\u3057\u305f\u3002\u3053\u3046\u3057\u305f\u80cc\u666f\u304b\u3089\u3001\u30dd\u30fc\u30c8587\u3068StartTLS\u306e\u5229\u7528\u304c\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u304a\u307e\u3051\uff1a\u30dd\u30fc\u30c82525\u3068\u306f?<\/h3>\n
\u30dd\u30fc\u30c8465\u3068\u30dd\u30fc\u30c8587\u306b\u3064\u3044\u3066\u306e\u8cea\u554f\u3067\u306f\u3001\u30dd\u30fc\u30c82525\u3078\u306e\u8a00\u53ca\u3082\u3088\u304f\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u30dd\u30fc\u30c8\u306f\u3069\u3046\u3044\u3063\u305f\u3082\u306e\u3067\u3001\u4f55\u306b\u5229\u7528\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3057\u3087\u3046\u304b\uff1f\u7b54\u3048\u306f\u3068\u3066\u3082\u7c21\u5358\u3067\u3059\u3002\u591a\u304f\u306eISP\u306f\u3001\u500b\u4eba\u304c\u81ea\u5206\u306e\u30e1\u30fc\u30eb\u30b5\u30fc\u30d0\u3092\u7acb\u3066\u308b\u3053\u3068\u3092\u9632\u3050\u305f\u3081\u306b\u3001\u30dd\u30fc\u30c825\u3092\u30d6\u30ed\u30c3\u30af\u3057\u307e\u3059\u3002\u3053\u306e\u30d6\u30ed\u30c3\u30af\u306e\u554f\u984c\u3092\u7de9\u548c\u3059\u308b\u305f\u3081\u306b\u3001\u591a\u304f\u306eESP\u304c\u4ee3\u66ff\u7b56\u3068\u3057\u3066\u30dd\u30fc\u30c82525\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
\u3069\u3061\u3089\u306e\u30dd\u30fc\u30c8\u3092\u4f7f\u3046\u3079\u304d\u304b?<\/h3>\n
\u591a\u304f\u306eESP\u3067\u306f\u3001\u30dd\u30fc\u30c8465\u3067\u6697\u9ed9\u7684TLS\u3092\u5229\u7528\u53ef\u80fd\u3067\u3059\u304c\u3001\u4e0a\u8ff0\u306e\u3088\u3046\u306b\u30dd\u30fc\u30c8587\u3092\u5229\u7528\u3059\u308b\u3053\u3068\u304c\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3082\u3061\u308d\u3093\u3001\u30e1\u30c3\u30bb\u30fc\u30b8\u3092\u6697\u53f7\u5316\u3057\u305f\u65b9\u304c\u5b89\u5168\u3067\u3042\u308b\u305f\u3081\u3001\u30dd\u30fc\u30c825\u30682525\u304c\u5229\u7528\u53ef\u80fd\u3067\u3042\u3063\u3066\u3082\u4f7f\u3046\u3079\u304d\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n
\u7d50\u8ad6\u3068\u3057\u3066\u3001\u3067\u304d\u308b\u3060\u3051\u30dd\u30fc\u30c8587\u3092\u4f7f\u3044\u3001\u305d\u308c\u304c\u96e3\u3057\u3044\u5834\u5408\u306f\u30dd\u30fc\u30c8465\u3092\u4f7f\u3046\u3068\u3044\u3046\u65b9\u91dd\u304c\u671b\u307e\u3057\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u3053\u306e\u8a18\u4e8b\u306f What\u2019s the Difference Between Ports 465 and 587? \u306e\u6284\u8a33\u3067\u3059\u3002 \u30e1\u30fc\u30eb\u9001\u4fe1\u8005\u306e\u7686\u3055\u3093\u304b\u3089\u3001\u30dd\u30fc\u30c8465\u3068587\u306e\u9055\u3044\u306b\u3064\u3044\u3066\u3088\u304f\u805e\u304b\u308c\u307e\u3059\u3002\u3053\u306e\u8cea\u554f\u306b\u6b63\u78ba\u306b\u7b54\u3048 …\u7d9a\u304d\u3092\u8aad\u3080<\/a><\/p>\n","protected":false},"author":2,"featured_media":16149,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[11],"tags":[],"class_list":["post-12945","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technical"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12945","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12945"}],"version-history":[{"count":10,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12945\/revisions"}],"predecessor-version":[{"id":16746,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/12945\/revisions\/16746"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=\/wp\/v2\/media\/16149"}],"wp:attachment":[{"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12945"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12945"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sendgrid.kke.co.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12945"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}