{"id":14172,"date":"2025-12-08T06:00:47","date_gmt":"2025-12-07T21:00:47","guid":{"rendered":"https:\/\/m365jp.net\/?p=14172"},"modified":"2025-12-08T06:04:43","modified_gmt":"2025-12-07T21:04:43","slug":"servicedegradation-ex1192586-exchange-online-some-users-may-be-unable-to-open-inbound-secure-multipurpose-internet-mail-extensions-s-mime-encrypted-email-messages-5","status":"publish","type":"post","link":"https:\/\/m365jp.net\/index.php\/2025-12-08-servicedegradation-ex1192586-exchange-online-some-users-may-be-unable-to-open-inbound-secure-multipurpose-internet-mail-extensions-s-mime-encrypted-email-messages-5","title":{"rendered":"[serviceDegradation] EX1192586 | Exchange Online | Some users may be unable to open inbound Secure\/Multipurpose Internet Mail Extensions (S\/MIME) encrypted email messages"},"content":{"rendered":"
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EX1192586 | Exchange Online | Some users may be unable to open inbound Secure\/Multipurpose Internet Mail Extensions (S\/MIME) encrypted email messages<\/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 open some inbound S\/MIME encrypted email messages in Exchange Online.<\/td>\n<\/tr>\n
Last Updated<\/th>\n12\/07\/2025 20:45:21<\/td>\n<\/tr>\n
Start Time<\/th>\n11\/30\/2025 00:00:00<\/td>\n<\/tr>\n
End Time<\/th>\n<\/td>\n<\/tr>\n
Latest Message<\/th>\nTitle: Some users may be unable to open inbound Secure\/Multipurpose Internet Mail Extensions (S\/MIME) encrypted email messages<\/p>\n

User impact: Users may be unable to open some inbound S\/MIME encrypted email messages in Exchange Online.<\/p>\n

More info: This issue strictly impacts users with the Dynamic Delivery policy enabled.<\/p>\n

We’ve disabled Dynamic Delivery “for S\/MIME messages” while we work to resolve this issue. <\/p>\n

Additionally, some users see a “Safe Attachments Scan in Progress” message upon opening an encrypted inbound email message.<\/p>\n

Current status: Our internal service telemetry has validated that our fix is addressing the problems, and that users have been able to open all new inbound S\/MIME encrypted email messages since Friday, December 5, at approximately 9:40 PM UTC. Following our completed fix deployment, we’re enabling the recovery of the previously undelivered messages, which is expected to be complete by our next scheduled communication update.<\/p>\n

Scope of impact: Some users with Dynamic Delivery enabled attempting to open S\/MIME encrypted email messages may be impacted.<\/p>\n

Start time: Sunday, November 30, 2025, at 12:00 AM UTC<\/p>\n

Root cause: A recent service update that intended to introduce a new Microsoft Defender for Office 365 feature incorrectly marked S\/MIME messages for delivery, resulting in impact. <\/p>\n

Next update by: Monday, December 8, 2025, at 6:30 PM UTC<\/td>\n<\/tr>\n

Machine Translation<\/th>\n\u30bf\u30a4\u30c8\u30eb:\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306f\u3001\u53d7\u4fe1\u3059\u308bSecure\/Multipurpose Internet Mail Extensions(S\/MIME)\u6697\u53f7\u5316\u30e1\u30fc\u30eb\u30e1\u30c3\u30bb\u30fc\u30b8\u3092\u958b\u3051\u3089\u308c\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059<\/p>\n

\u30e6\u30fc\u30b6\u30fc\u3078\u306e\u5f71\u97ff:\u30e6\u30fc\u30b6\u30fc\u306fExchange Online\u3067\u4e00\u90e8\u306e\u53d7\u4fe1S\/MIME\u6697\u53f7\u5316\u30e1\u30fc\u30eb\u30e1\u30c3\u30bb\u30fc\u30b8\u3092\u958b\u3051\u3089\u308c\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u8a73\u7d30:\u3053\u306e\u554f\u984c\u306f\u52d5\u7684\u914d\u9001\u30dd\u30ea\u30b7\u30fc\u304c\u6709\u52b9\u306b\u306a\u3063\u3066\u3044\u308b\u30e6\u30fc\u30b6\u30fc\u306b\u9650\u5b9a\u7684\u306b\u767a\u751f\u3057\u307e\u3059\u3002<\/p>\n

\u3053\u306e\u554f\u984c\u306e\u89e3\u6c7a\u306b\u53d6\u308a\u7d44\u3080\u9593\u3001\u300cS\/MIME\u30e1\u30c3\u30bb\u30fc\u30b8\u300d\u306e\u52d5\u7684\u914d\u4fe1\u3092\u7121\u52b9\u306b\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n

\u3055\u3089\u306b\u3001\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306f\u6697\u53f7\u5316\u3055\u308c\u305f\u53d7\u4fe1\u30e1\u30fc\u30eb\u3092\u958b\u304f\u3068\u300cSafe Attachments Scan in Progress\u300d\u3068\u3044\u3046\u30e1\u30c3\u30bb\u30fc\u30b8\u304c\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n

\u73fe\u72b6:\u5f53\u793e\u306e\u5185\u90e8\u30b5\u30fc\u30d3\u30b9\u30c6\u30ec\u30e1\u30c8\u30ea\u306b\u3088\u308a\u3001\u4fee\u6b63\u304c\u554f\u984c\u306b\u5bfe\u51e6\u3057\u3066\u3044\u308b\u3053\u3068\u304c\u78ba\u8a8d\u3055\u308c\u3066\u304a\u308a\u3001\u30e6\u30fc\u30b6\u30fc\u306f12\u67085\u65e5\u91d1\u66dc\u65e5\u5348\u5f8c9\u664240\u5206\u9803(UTC)\u4ee5\u964d\u3001\u3059\u3079\u3066\u306e\u65b0\u3057\u3044\u53d7\u4fe1S\/MIME\u6697\u53f7\u5316\u30e1\u30fc\u30eb\u3092\u958b\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002 \u4fee\u6b63\u5c55\u958b\u5b8c\u4e86\u5f8c\u3001\u3053\u308c\u307e\u3067\u914d\u4fe1\u3055\u308c\u306a\u304b\u3063\u305f\u30e1\u30c3\u30bb\u30fc\u30b8\u306e\u5fa9\u65e7\u3092\u53ef\u80fd\u306b\u3057\u3066\u304a\u308a\u3001\u6b21\u56de\u306e\u4e88\u5b9a\u3055\u308c\u305f\u901a\u4fe1\u66f4\u65b0\u307e\u3067\u306b\u5b8c\u4e86\u3059\u308b\u4e88\u5b9a\u3067\u3059\u3002<\/p>\n

\u5f71\u97ff\u7bc4\u56f2:\u52d5\u7684\u914d\u4fe1\u304c\u6709\u52b9\u3067\u3042\u308b\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306f\u3001S\/MIME\u6697\u53f7\u5316\u3055\u308c\u305f\u30e1\u30fc\u30eb\u30e1\u30c3\u30bb\u30fc\u30b8\u3092\u958b\u3053\u3046\u3068\u3059\u308b\u3068\u5f71\u97ff\u3092\u53d7\u3051\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u958b\u59cb\u6642\u9593:2025\u5e7411\u670830\u65e5(\u65e5)0:00 UTC<\/p>\n

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\u6b21\u56de\u66f4\u65b0:2025\u5e7412\u67088\u65e5(\u6708)\u5348\u5f8c6\u664230\u5206 UTC<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

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