{"id":14448,"date":"2026-01-08T22:01:17","date_gmt":"2026-01-08T13:01:17","guid":{"rendered":"https:\/\/m365jp.net\/?p=14448"},"modified":"2026-01-08T22:06:32","modified_gmt":"2026-01-08T13:06:32","slug":"servicerestored-ex1215307-exchange-online-some-users-may-have-been-unable-to-access-their-mailboxes-using-internet-mailbox-access-protocol-4-imap4","status":"publish","type":"post","link":"https:\/\/m365jp.net\/index.php\/2026-01-08-servicerestored-ex1215307-exchange-online-some-users-may-have-been-unable-to-access-their-mailboxes-using-internet-mailbox-access-protocol-4-imap4","title":{"rendered":"[serviceRestored] EX1215307 | Exchange Online | Some users may have been unable to access their mailboxes using Internet Mailbox Access Protocol 4 (IMAP4)"},"content":{"rendered":"
\n
\n
\n\n\n\n
EX1215307 | Exchange Online | Some users may have been unable to access their mailboxes using Internet Mailbox Access Protocol 4 (IMAP4) <\/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>\nincident<\/td>\n<\/tr>\n
User Impact<\/th>\nUsers may have intermittently been unable to access their mailboxes using IMAP4. <\/td>\n<\/tr>\n
Last Updated<\/th>\n01\/08\/2026 12:34:33<\/td>\n<\/tr>\n
Start Time<\/th>\n01\/02\/2026 00:00:00<\/td>\n<\/tr>\n
End Time<\/th>\n01\/08\/2026 11:30:00<\/td>\n<\/tr>\n
Latest Message<\/th>\nTitle: Some users may have been unable to access their mailboxes using Internet Mailbox Access Protocol 4 (IMAP4) <\/p>\n

User impact: Users may have intermittently been unable to access their mailboxes using IMAP4. <\/p>\n

More info: Impact was specific to IMAP4, other connection methods were not impacted. Additionally, if users were actively facing this issue, retries may have been successful. <\/p>\n

Final status: We\u2019ve completed deploying the configuration change on the affected servers, which reduced volume and restored normal service functionality. After a period of monitoring, we\u2019ve confirmed that impact has been fully remediated. <\/p>\n

Scope of impact: Some users that were attempting to access their mailboxes using IMAP4 may have been intermittently impacted. <\/p>\n

Start time: Friday, January 2, 2026, at 12:00 AM UTC<\/p>\n

End time: Thursday, January 8, 2026, at 11:30 AM UTC<\/p>\n

Root cause: A recent IMAP deployment related to authentication support contained a code conflict that introduced a configuration issue and was causing intermittent mailbox access issues for some impacted users.<\/p>\n

Next steps:
– We’re reviewing our deployment and provisioning procedures to help prevent similar problems 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\u306f\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u90f5\u4fbf\u7bb1\u30a2\u30af\u30bb\u30b9\u30d7\u30ed\u30c8\u30b3\u30eb4(IMAP4)\u3092\u4f7f\u7528\u3057\u3066\u81ea\u5206\u306e\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u304b\u3063\u305f\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u30e6\u30fc\u30b6\u30fc\u3078\u306e\u5f71\u97ff:IMAP4\u3092\u4f7f\u3063\u3066\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u8a73\u7d30\u60c5\u5831:\u30a4\u30f3\u30d1\u30af\u30c8\u306fIMAP4\u7279\u6709\u306e\u3082\u306e\u3067\u3001\u4ed6\u306e\u63a5\u7d9a\u65b9\u6cd5\u306f\u5f71\u97ff\u3092\u53d7\u3051\u3066\u3044\u307e\u305b\u3093\u3002\u3055\u3089\u306b\u3001\u30e6\u30fc\u30b6\u30fc\u304c\u3053\u306e\u554f\u984c\u306b\u7a4d\u6975\u7684\u306b\u76f4\u9762\u3057\u3066\u3044\u308c\u3070\u3001\u518d\u8a66\u884c\u306f\u6210\u529f\u3057\u3066\u3044\u305f\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u6700\u7d42\u72b6\u6cc1:\u5f71\u97ff\u3092\u53d7\u3051\u305f\u30b5\u30fc\u30d0\u30fc\u3078\u306e\u8a2d\u5b9a\u5909\u66f4\u306e\u5c55\u958b\u3092\u5b8c\u4e86\u3057\u3001\u30dc\u30ea\u30e5\u30fc\u30e0\u304c\u6e1b\u5c11\u3057\u901a\u5e38\u306e\u30b5\u30fc\u30d3\u30b9\u6a5f\u80fd\u304c\u56de\u5fa9\u3057\u307e\u3057\u305f\u3002\u4e00\u5b9a\u671f\u9593\u306e\u76e3\u8996\u306e\u7d50\u679c\u3001\u5f71\u97ff\u306f\u5b8c\u5168\u306b\u4fee\u5fa9\u3055\u308c\u305f\u3053\u3068\u304c\u78ba\u8a8d\u3055\u308c\u307e\u3057\u305f\u3002<\/p>\n

\u5f71\u97ff\u7bc4\u56f2:IMAP4\u3092\u4f7f\u3063\u3066\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u306b\u30a2\u30af\u30bb\u30b9\u3057\u3088\u3046\u3068\u3057\u305f\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u306f\u65ad\u7d9a\u7684\u306b\u5f71\u97ff\u3092\u53d7\u3051\u305f\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u958b\u59cb\u6642\u9593:2026\u5e741\u67082\u65e5\u91d1\u66dc\u65e5 0:00 UTC<\/p>\n

\u7d42\u4e86\u6642\u523b:2026\u5e741\u67088\u65e5\u6728\u66dc\u65e5 \u5348\u524d11\u664230\u5206 UTC<\/p>\n

\u6839\u672c\u539f\u56e0:\u8a8d\u8a3c\u30b5\u30dd\u30fc\u30c8\u306b\u95a2\u9023\u3059\u308b\u6700\u8fd1\u306eIMAP\u5c0e\u5165\u3067\u306f\u30b3\u30fc\u30c9\u306e\u7af6\u5408\u304c\u767a\u751f\u3057\u3001\u8a2d\u5b9a\u306e\u554f\u984c\u304c\u767a\u751f\u3057\u3001\u4e00\u90e8\u306e\u30e6\u30fc\u30b6\u30fc\u3067\u65ad\u7d9a\u7684\u306b\u30e1\u30fc\u30eb\u30dc\u30c3\u30af\u30b9\u3078\u306e\u30a2\u30af\u30bb\u30b9\u306b\u554f\u984c\u304c\u767a\u751f\u3057\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n

\u6b21\u306e\u30b9\u30c6\u30c3\u30d7:
– \u4eca\u5f8c\u540c\u69d8\u306e\u554f\u984c\u3092\u9632\u3050\u305f\u3081\u3001\u5c55\u958b\u304a\u3088\u3073\u30d7\u30ed\u30d3\u30b8\u30e7\u30cb\u30f3\u30b0\u624b\u9806\u3092\u898b\u76f4\u3057\u3066\u3044\u307e\u3059\u3002 <\/p>\n

\u3053\u308c\u304c\u30a4\u30d9\u30f3\u30c8\u306e\u6700\u7d42\u30a2\u30c3\u30d7\u30c7\u30fc\u30c8\u3067\u3059\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

EX1215307 | Exchange Online | Some users may have been unable to access their mailboxes using Internet Mailbox […]<\/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-14448","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/14448","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=14448"}],"version-history":[{"count":0,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/posts\/14448\/revisions"}],"wp:attachment":[{"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/media?parent=14448"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/categories?post=14448"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/m365jp.net\/index.php\/wp-json\/wp\/v2\/tags?post=14448"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}