{"id":15554,"date":"2026-03-24T13:01:24","date_gmt":"2026-03-24T04:01:24","guid":{"rendered":"https:\/\/m365jp.net\/?p=15554"},"modified":"2026-03-24T13:07:00","modified_gmt":"2026-03-24T04:07:00","slug":"servicerestored-ex1259159-exchange-online-some-users-outbound-email-messages-may-display-an-unexpected-sender-name-in-exchange-online","status":"publish","type":"post","link":"https:\/\/m365jp.net\/index.php\/2026-03-24-servicerestored-ex1259159-exchange-online-some-users-outbound-email-messages-may-display-an-unexpected-sender-name-in-exchange-online","title":{"rendered":"[serviceRestored] EX1259159 | Exchange Online | Some users\u2019 outbound email messages may display an unexpected sender name in Exchange Online"},"content":{"rendered":"
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EX1259159 | Exchange Online | Some users\u2019 outbound email messages may display an unexpected sender name in Exchange Online<\/th>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\n\n\n\n\n\n\n\n\n\n
Status<\/th>\nserviceRestored<\/td>\n<\/tr>\n
Classification<\/th>\nadvisory<\/td>\n<\/tr>\n
User Impact<\/th>\nUsers\u2019 outbound email messages may have displayed an unexpected sender name in Exchange Online.<\/td>\n<\/tr>\n
Last Updated<\/th>\n03\/24\/2026 03:27:25<\/td>\n<\/tr>\n
Start Time<\/th>\n03\/05\/2026 22:00:00<\/td>\n<\/tr>\n
End Time<\/th>\n03\/23\/2026 18:40:00<\/td>\n<\/tr>\n
Latest Message<\/th>\nTitle: Some users\u2019 outbound email messages may display an unexpected sender name in Exchange Online<\/p>\n

User impact: Users\u2019 outbound email messages may have displayed an unexpected sender name in Exchange Online.<\/p>\n

More info: When affected users sent email to external recipients, the sender name shown may have been the mailbox DisplayName instead of the configured SimpleDisplayName.<\/p>\n

Final status: We’ve confirmed through internal testing that impact is no longer occurring. While no further outbound messages should be impacted, email messages that were already sent with the unexpected sender name will continue to show the sender name used when originally sent.<\/p>\n

Scope of impact: Some users sending email to external recipients in Exchange Online may have been impacted.<\/p>\n

Start time: Thursday, March 5, 2026, at 10:00 PM UTC<\/p>\n

End time: Monday, March 23, 2026, at 6:40 PM UTC<\/p>\n

Root cause: A recent service update introduced new outbound mail behavior that caused Exchange Online to stop honoring the configured SimpleDisplayName in some outbound email scenarios, resulting in impact.<\/p>\n

Next steps:
– We’re reviewing our update testing and validation methods to better identify issues such as this prior to deployment so we can prevent similar impact in the future.<\/p>\n

This is the final update for the event.<\/td>\n<\/tr>\n

Machine Translation<\/th>\n\u30bf\u30a4\u30c8\u30eb:\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306e\u9001\u4fe1\u30e1\u30fc\u30eb\u306b\u3001Exchange Online\u3067\u4e88\u671f\u3057\u306a\u3044\u9001\u4fe1\u8005\u540d\u304c\u8868\u793a\u3055\u308c\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059<\/p>\n

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\u8a73\u7d30\u60c5\u5831:\u5f71\u97ff\u3092\u53d7\u3051\u305f\u30e6\u30fc\u30b6\u30fc\u304c\u5916\u90e8\u53d7\u4fe1\u8005\u306b\u30e1\u30fc\u30eb\u3092\u9001\u4fe1\u3057\u305f\u969b\u3001\u8868\u793a\u3055\u308c\u305f\u9001\u4fe1\u8005\u540d\u304c\u8a2d\u5b9a\u3055\u308c\u305fSimpleDisplayName\u3067\u306f\u306a\u304f\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9DisplayName\u3060\u3063\u305f\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u6700\u7d42\u72b6\u6cc1:\u5185\u90e8\u30c6\u30b9\u30c8\u306b\u3088\u308a\u3001\u5f71\u97ff\u306f\u3082\u306f\u3084\u767a\u751f\u3057\u3066\u3044\u306a\u3044\u3053\u3068\u304c\u78ba\u8a8d\u3055\u308c\u307e\u3057\u305f\u3002\u3053\u308c\u4ee5\u4e0a\u306e\u9001\u4fe1\u30e1\u30c3\u30bb\u30fc\u30b8\u306f\u5f71\u97ff\u3092\u53d7\u3051\u307e\u305b\u3093\u304c\u3001\u4e88\u671f\u3057\u306a\u3044\u9001\u4fe1\u8005\u540d\u3067\u65e2\u306b\u9001\u4fe1\u3055\u308c\u305f\u30e1\u30fc\u30eb\u306f\u3001\u6700\u521d\u306b\u9001\u4fe1\u3055\u308c\u305f\u9001\u4fe1\u8005\u540d\u304c\u5f15\u304d\u7d9a\u304d\u8868\u793a\u3055\u308c\u307e\u3059\u3002<\/p>\n

\u5f71\u97ff\u7bc4\u56f2:Exchange Online\u3067\u5916\u90e8\u53d7\u4fe1\u8005\u306b\u30e1\u30fc\u30eb\u3092\u9001\u4fe1\u3059\u308b\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306f\u5f71\u97ff\u3092\u53d7\u3051\u305f\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u958b\u59cb\u6642\u9593:2026\u5e743\u67085\u65e5\u6728\u66dc\u65e5 22:00 UTC<\/p>\n

\u7d42\u4e86\u6642\u523b:2026\u5e743\u670823\u65e5(\u6708)\u5348\u5f8c6\u664240\u5206(UTC)<\/p>\n

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\u6b21\u306e\u30b9\u30c6\u30c3\u30d7:
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EX1259159 | Exchange Online | Some users\u2019 outbound email messages may display an unexpected sender name in 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-15554","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/15554","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=15554"}],"version-history":[{"count":0,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/15554\/revisions"}],"wp:attachment":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/media?parent=15554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/categories?post=15554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/tags?post=15554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}