{"id":18335,"date":"2026-09-04T02:02:01","date_gmt":"2026-09-03T17:02:01","guid":{"rendered":"https:\/\/m365jp.net\/?p=18335"},"modified":"2026-09-04T02:05:21","modified_gmt":"2026-09-03T17:05:21","slug":"servicedegradation-ex1464935-exchange-online-users-may-be-unable-to-connect-to-or-experience-degraded-functionality-with-exchange-online-24","status":"publish","type":"post","link":"https:\/\/m365jp.net\/index.php\/2026-09-04-servicedegradation-ex1464935-exchange-online-users-may-be-unable-to-connect-to-or-experience-degraded-functionality-with-exchange-online-24","title":{"rendered":"[serviceDegradation] EX1464935 | Exchange Online | Users may be unable to connect to, or experience degraded functionality with Exchange Online"},"content":{"rendered":"
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EX1464935 | Exchange Online | Users may be unable to connect to, or experience degraded functionality with Exchange Online<\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\n\n\n\n\n\n\n\n\n\n
Status<\/th>\nserviceDegradation<\/td>\n<\/tr>\n
Classification<\/th>\nincident<\/td>\n<\/tr>\n
User Impact<\/th>\nUsers may be unable to connect to, or experience degraded functionality with Exchange Online.<\/td>\n<\/tr>\n
Last Updated<\/th>\n09\/03\/2026 16:23:14<\/td>\n<\/tr>\n
Start Time<\/th>\n08\/31\/2026 15:08:00<\/td>\n<\/tr>\n
End Time<\/th>\n<\/td>\n<\/tr>\n
Latest Message<\/th>\nTitle: Users may be unable to connect to, or experience degraded functionality with Exchange Online<\/p>\n

User impact: Users may be unable to connect to, or experience degraded functionality with Exchange Online.<\/p>\n

More info: We’ve confirmed that the authentication component issue impacts other services beyond Exchange Online. For more information regarding other impact scenarios, please see: MO1465074.<\/p>\n

We’ve opted to keep this post (EX1464935) open as Exchange Online remains the most predominantly impacted service.<\/p>\n

Users may experience a variety of symptoms related to this event, including but not limited to:
– Users can’t download email message attachments through any Exchange Online connection method.
– Delays, failures, or incomplete results when searching for content within Exchange Online mailboxes.
– Delays or failures when sending or receiving email messages.
– Authentication-related errors when accessing Exchange Online services.
– Difficulties accessing or performing actions within Exchange administration experiences.
– Intermittent failures affecting mailbox operations and message delivery work
– Delays or failures when sending or receiving email messages via Outlook for iOS and Android.
– Users may be unable to use room finder in Outlook calendars.
– Users may be unable to sign in to Outlook on the web.<\/p>\n

Current status: We discovered an issue in less than one percent of our infrastructure, where our additional mitigation efforts to resolve impact for Exchange Online did not successfully deploy. The vast majority of impact remains remediated; however, those serviced from the impacted portion of infrastructure may be unable to access previously recovered Outlook connection methods. We remain committed to restoring all services to all users and will continue to carefully monitor our telemetry to ensure recovery.<\/p>\n

Scope of impact: Users attempting to perform any of the outlined impact scenarios may be affected by this event.<\/p>\n

Start time: Monday, August 31, 2026, at 3:08 PM UTC<\/p>\n

Preliminary root cause: An issue within a core authentication configuration used by multiple Microsoft 365 services is resulting in impact.<\/p>\n

Next update by: Thursday, September 3, 2026, at 6:30 PM UT<\/td>\n<\/tr>\n

Machine Translation<\/th>\n\u30bf\u30a4\u30c8\u30eb:\u30e6\u30fc\u30b6\u30fc\u304cExchange Online\u306b\u63a5\u7d9a\u3067\u304d\u306a\u304f\u306a\u3063\u305f\u308a\u3001\u6a5f\u80fd\u304c\u52a3\u5316\u3057\u3066\u3044\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059<\/p>\n

\u30e6\u30fc\u30b6\u30fc\u3078\u306e\u5f71\u97ff:\u30e6\u30fc\u30b6\u30fc\u306fExchange Online\u306b\u63a5\u7d9a\u3067\u304d\u306a\u304f\u306a\u3063\u305f\u308a\u3001\u6a5f\u80fd\u306e\u4f4e\u4e0b\u3092\u611f\u3058\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u8a73\u7d30\u60c5\u5831:\u8a8d\u8a3c\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u554f\u984c\u306fExchange Online\u4ee5\u5916\u306e\u30b5\u30fc\u30d3\u30b9\u306b\u3082\u5f71\u97ff\u304c\u3042\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u307e\u3057\u305f\u3002\u305d\u306e\u4ed6\u306e\u5f71\u97ff\u30b7\u30ca\u30ea\u30aa\u306b\u3064\u3044\u3066\u306f\u3001MO1465074\u3092\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n

Exchange Online\u304c\u6700\u3082\u5927\u304d\u306a\u5f71\u97ff\u3092\u53d7\u3051\u3066\u3044\u308b\u30b5\u30fc\u30d3\u30b9\u3067\u3042\u308b\u305f\u3081\u3001\u3053\u306e\u6295\u7a3f(EX1464935)\u306f\u958b\u3044\u305f\u307e\u307e\u306b\u3059\u308b\u3053\u3068\u306b\u3057\u307e\u3057\u305f\u3002<\/p>\n

\u5229\u7528\u8005\u306f\u3053\u306e\u51fa\u6765\u4e8b\u306b\u95a2\u9023\u3059\u308b\u3055\u307e\u3056\u307e\u306a\u75c7\u72b6\u3092\u7d4c\u9a13\u3059\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u4ee5\u4e0b\u306b\u9650\u5b9a\u3055\u308c\u307e\u305b\u3093\u3002
– \u30e6\u30fc\u30b6\u30fc\u306fExchange Online\u306e\u63a5\u7d9a\u65b9\u6cd5\u3092\u901a\u3058\u3066\u30e1\u30fc\u30eb\u6dfb\u4ed8\u30d5\u30a1\u30a4\u30eb\u3092\u30c0\u30a6\u30f3\u30ed\u30fc\u30c9\u3067\u304d\u307e\u305b\u3093\u3002
– Exchange Online\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u5185\u3067\u30b3\u30f3\u30c6\u30f3\u30c4\u3092\u691c\u7d22\u3059\u308b\u969b\u306e\u9045\u5ef6\u3001\u5931\u6557\u3001\u307e\u305f\u306f\u4e0d\u5b8c\u5168\u306a\u7d50\u679c\u3002
– \u30e1\u30fc\u30eb\u306e\u9001\u53d7\u4fe1\u306b\u304a\u3051\u308b\u9045\u5ef6\u3084\u5931\u6557\u3002
– Exchange Online\u30b5\u30fc\u30d3\u30b9\u3078\u306e\u30a2\u30af\u30bb\u30b9\u6642\u306e\u8a8d\u8a3c\u95a2\u9023\u30a8\u30e9\u30fc\u3002
– \u53d6\u5f15\u6240\u7ba1\u7406\u4f53\u9a13\u5185\u3067\u306e\u64cd\u4f5c\u3084\u30a2\u30af\u30bb\u30b9\u306e\u56f0\u96e3\u3002
– \u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u64cd\u4f5c\u3084\u30e1\u30c3\u30bb\u30fc\u30b8\u914d\u4fe1\u4f5c\u696d\u306b\u5f71\u97ff\u3092\u4e0e\u3048\u308b\u65ad\u7d9a\u7684\u306a\u969c\u5bb3
– Outlook(iOS\u304a\u3088\u3073Android)\u3067\u306e\u30e1\u30fc\u30eb\u9001\u53d7\u4fe1\u306e\u9045\u5ef6\u3084\u5931\u6557\u3002
– \u30e6\u30fc\u30b6\u30fc\u306fOutlook\u306e\u30ab\u30ec\u30f3\u30c0\u30fc\u3067\u30eb\u30fc\u30e0\u30d5\u30a1\u30a4\u30f3\u30c0\u30fc\u3092\u4f7f\u3048\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002
– \u30e6\u30fc\u30b6\u30fc\u306f\u30a6\u30a7\u30d6\u4e0a\u306eOutlook\u306b\u30b5\u30a4\u30f3\u30a4\u30f3\u3067\u304d\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u73fe\u72b6:\u30a4\u30f3\u30d5\u30e9\u306e1%\u672a\u6e80\u3067\u554f\u984c\u3092\u767a\u898b\u3057\u307e\u3057\u305f\u3002Exchange Online\u3078\u306e\u5f71\u97ff\u3092\u89e3\u6c7a\u3059\u308b\u305f\u3081\u306e\u8ffd\u52a0\u306e\u7de9\u548c\u7b56\u304c\u6210\u529f\u88cf\u306b\u5c55\u958b\u3055\u308c\u306a\u304b\u3063\u305f\u306e\u3067\u3059\u3002\u5f71\u97ff\u306e\u5927\u90e8\u5206\u306f\u4f9d\u7136\u3068\u3057\u3066\u4fee\u5fa9\u6e08\u307f\u3067\u3059\u3002\u305f\u3060\u3057\u3001\u5f71\u97ff\u3092\u53d7\u3051\u305f\u30a4\u30f3\u30d5\u30e9\u90e8\u5206\u304b\u3089\u30b5\u30fc\u30d3\u30b9\u3092\u53d7\u3051\u305f\u30e6\u30fc\u30b6\u30fc\u306f\u3001\u4ee5\u524d\u306b\u5fa9\u5143\u3055\u308c\u305fOutlook\u63a5\u7d9a\u65b9\u6cd5\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u3044\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002\u79c1\u305f\u3061\u306f\u3059\u3079\u3066\u306e\u30e6\u30fc\u30b6\u30fc\u306b\u3059\u3079\u3066\u306e\u30b5\u30fc\u30d3\u30b9\u3092\u5fa9\u65e7\u3055\u305b\u308b\u3053\u3068\u306b\u5f15\u304d\u7d9a\u304d\u30b3\u30df\u30c3\u30c8\u3057\u3001\u30c6\u30ec\u30e1\u30c8\u30ea\u3092\u6ce8\u610f\u6df1\u304f\u76e3\u8996\u3057\u3066\u56de\u5fa9\u3092\u78ba\u5b9f\u306b\u3057\u307e\u3059\u3002<\/p>\n

\u5f71\u97ff\u7bc4\u56f2:\u4e0a\u8a18\u306e\u5f71\u97ff\u30b7\u30ca\u30ea\u30aa\u306e\u3044\u305a\u308c\u304b\u3092\u5b9f\u884c\u3057\u3088\u3046\u3068\u3059\u308b\u30e6\u30fc\u30b6\u30fc\u306f\u3001\u3053\u306e\u30a4\u30d9\u30f3\u30c8\u306e\u5f71\u97ff\u3092\u53d7\u3051\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u958b\u59cb\u6642\u9593:2026\u5e748\u670831\u65e5(\u6708)\u5348\u5f8c3\u664208\u5206(UTC)<\/p>\n

\u4e88\u5099\u7684\u306a\u6839\u672c\u539f\u56e0:\u8907\u6570\u306eMicrosoft 365\u30b5\u30fc\u30d3\u30b9\u3067\u4f7f\u7528\u3055\u308c\u308b\u30b3\u30a2\u8a8d\u8a3c\u69cb\u6210\u306e\u554f\u984c\u304c\u5f71\u97ff\u3092\u53ca\u307c\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u6b21\u56de\u66f4\u65b0:2026\u5e749\u67083\u65e5\u6728\u66dc\u65e5 \u5348\u5f8c6\u664230\u5206 UT<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

EX1464935 | Exchange Online | Users may be unable to connect to, or experience degraded functionality with Exc […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-18335","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/18335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/comments?post=18335"}],"version-history":[{"count":0,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/18335\/revisions"}],"wp:attachment":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/media?parent=18335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/categories?post=18335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/tags?post=18335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}