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Shared Outlook Calendar disappeared
An Outlook Calendar that my wife and I share has suddenly disappeared from my Outlook Calendar. It still shows on my wife's computer. We set this up a number of years ago, so I have no idea where or how to troubleshoot this. I do recall that we had to each create outlook.com email addresses so that we could access Microsoft Exchange. We are using the Classic version of Outlook. In case it's useful, here's the exact information from the Outlook About page: "Microsoft® Outlook® for Microsoft 365 MSO (Version 2605 Build 16.0.20026.20168) 64-bit." Thanks to anyone who can help me solve this problem.New Outlook Offline Mode: Add and open attachments while offline
Microsoft has been rolling out offline functionality in phases, and the latest update now allows users to add and open attachments while offline. I created a short walkthrough covering what works offline now, what users need to know about attaching files from OneDrive versus local drives, and which features still require an internet connection. I also shared my discoveries when creating a calendar event that you don't want to miss. Video: https://www.youtube.com/watch?v=SYsraZBTack traccreations4e-p26 6/15/2026
Outlook 16.109.3 crashes on launch on macOS 26 (Tahoe beta) - UTI Info.plist regression
Environment: macOS 26.5.1 Build 25F80 (Tahoe beta) - Microsoft Outlook 16.109.3 (build 26053122) - MacBook Air Mac14,2 arm64, 16GB Issue: Outlook crashes immediately on every launch. Occurs on clean install with no profile. Tested two builds (26053122 and 26051019) - both crash identically. Root cause from system logs: macOS 26 has tightened UniformTypeIdentifiers enforcement. Outlook's Info.plist is missing explicit declarations for 12+ com.microsoft UTI types. On every launch: "UniformTypeIdentifiers: Type 'com.microsoft.DataObject' was expected to be declared and exported in the Info.plist of Microsoft Outlook.app, but it was not found." Same error fires for: com.microsoft.Embedded-Object, EMF-Plus, GIF-Office-Art, Ink-Serialized-Format, JFIF-Office-Art, Link-Source-Descriptor, Object-Descriptor, Embed-Source, PNG-Office-Art, Office-Drawing-Drag-Drop-Format, Office-Drawing-Shape-Format. Secondary error: /private/var/db/DetachedSignatures does not exist on macOS 26, causing an SQLite open failure in libsqlite3. Workaround: None. Outlook Web only until a fix ships. Ask: Please update Outlook's Info.plist to explicitly declare all com.microsoft UTI types to comply with macOS 26's stricter enforcement. This will affect all Microsoft 365 Mac apps when macOS 26 ships publicly this fall.
New desktop outlook do not show incoming message in conversation
Hello. I would like to ask you about solution for this problem in new Outlook. I send message and i got reply for this message. This message i see as conversation in Inbox. When i collapse this conversation, i see only my original message, not reply message. But reply message I see only in header in list of mail, i can't open this message. Where can be problem? ThxIMAP connection error INVALIDCREDENTIALS
I am trying to add my external IMAP mailbox from my hosting provider (Easyhost.be) to the new Outlook app / Outlook.com. However, when I try to add this mailbox to my domain 'vinedo.be', I immediately receive the error message: INVALIDCREDENTIALS INTERACTIONREQUIRED. In the classic Outlook desktop app, the account works immediately via IMAP with exactly the same password. Everything also works perfectly with the Outlook app on an Android smartphone. There appears to be an incorrect tenant attribution or cache in the background of the Microsoft Cloud that is internally blocking authentication for the domain vinedo.be. Could you clear the cache/tenant attribution for the domain vinedo.be so that the IMAP connection is routed externally again? The mailbox email address removed for privacy reasons was hosted by Gandi.net until recently. This is presumably causing the problem.
Problem adding IMAP email account to Outlook on Android
I am trying to add a couple of IMAP email accounts to Outlook on Android. Both are for my own domain, and I already have both added to Outlook on my windows laptop without any issues. One of the emails, "name@ domain . com" is added without any problems on Android, but my catch-all email, "*@ domain . com" will not add, and constantly gives the "check email/password" error. This email works with Outlook on my windows PC, and with other email apps on Android. I suspect the problem is due to the *@ domain address, but my email provider says it should work with Outlook, and it already works on Windows Outlook. Has anyone seen this before? Stephen.
Classic Outlook event-based add-in: fetch/XMLHttpRequest fails in JavaScript-only runtime
We are testing outbound HTTP from an Outlook add-in event-based activation handler running in the classic Outlook for Windows JavaScript-only runtime used by: <Override type="javascript" resid="JSRuntime.Url"/> Question Is response-bearing HTTP via fetch or XMLHttpRequest officially supported from the classic Outlook for Windows JavaScript-only event runtime? If it is supported: Are there additional manifest, policy, trust, or runtime requirements beyond: absolute HTTPS URLs, <AppDomains>, .well-known/microsoft-officeaddins-allowed.json, Office.actions.associate(...), and using a single bundled JS file? If it is not supported or unreliable in this runtime: What is the recommended/supported pattern for an OnAppointmentSend handler that requires a server-side validation decision before allowing send? We are currently considering this workaround architecture: Precompute the validation result in the taskpane/WebView runtime. Store the decision in Outlook custom properties. Read the stored value from events.js during OnAppointmentSend. Is this workaround required, or should direct outbound HTTP from the event runtime work reliably? Environment Client tested: Microsoft Outlook 2016 MSO Version 2604 Build 16.0.19929.20172 32-bit Platform logged by Office.js: Office.context.platform === "PC" The launch event itself works correctly: OnAppointmentSendHandler is invoked. Office.actions.associate(...) works. event.completed(...) is delivered to Outlook successfully. The issue is specifically that response-bearing HTTP from events.js does not complete reliably. Relevant manifest excerpt <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides/1.1" xsi:type="VersionOverridesV1_1"> <Requirements> <bt:Sets DefaultMinVersion="1.12"> <bt:Set Name="Mailbox" /> </bt:Sets> </Requirements> <Hosts> <Host xsi:type="MailHost"> <Runtimes> <Runtime resid="WebViewRuntime.Url" lifetime="short"> <Override type="javascript" resid="JSRuntime.Url" /> </Runtime> </Runtimes> <DesktopFormFactor> <ExtensionPoint xsi:type="LaunchEvent"> <LaunchEvents> <LaunchEvent Type="OnAppointmentSend" FunctionName="OnAppointmentSendHandler" SendMode="SoftBlock" /> </LaunchEvents> <SourceLocation resid="WebViewRuntime.Url" /> </ExtensionPoint> </DesktopFormFactor> </Host> </Hosts> <Resources> <bt:Urls> <bt:Url id="WebViewRuntime.Url" DefaultValue="https://example-addin-host.example.com" /> <bt:Url id="JSRuntime.Url" DefaultValue="https://example-addin-host.example.com/events.js?v=2.0.0.16" /> </bt:Urls> </Resources> </VersionOverrides> Well-known event runtime CORS configuration We also configured the documented well-known URI for event runtime CORS: { "allowed": [ "https://example-addin-host.example.com/events.js?v=2.0.0.16" ] } Hosted at: https://example-addin-host.example.com/.well-known/microsoft-officeaddins-allowed.json Minimal events.js repro (function (root) { function OnAppointmentSendHandler(event) { console.log('[test] handler triggered', { hasFetch: typeof fetch, hasXMLHttpRequest: typeof XMLHttpRequest, platform: Office.context.platform }); var fetchStartedAt = Date.now(); setTimeout(function () { console.log('[test] fetch still pending', { elapsedMs: Date.now() - fetchStartedAt }); }, 4500); fetch('https://example-addin-host.example.com/manifest.xml', { method: 'GET', cache: 'no-store' }).then( function (response) { console.log('[test] fetch response', { elapsedMs: Date.now() - fetchStartedAt, ok: response.ok, status: response.status, statusText: response.statusText, url: response.url }); return response.text(); }, function (error) { console.log('[test] fetch error', { elapsedMs: Date.now() - fetchStartedAt, name: error && error.name, message: error && error.message }); } ); var xhrStartedAt = Date.now(); var xhr = new XMLHttpRequest(); xhr.timeout = 4500; xhr.onreadystatechange = function () { console.log('[test] xhr readyState', { elapsedMs: Date.now() - xhrStartedAt, readyState: xhr.readyState, status: xhr.status, statusText: xhr.statusText, responseURL: xhr.responseURL, responseTextLength: xhr.responseText ? xhr.responseText.length : 0 }); }; xhr.onload = function () { console.log('[test] xhr load', { elapsedMs: Date.now() - xhrStartedAt, status: xhr.status, responseTextLength: xhr.responseText ? xhr.responseText.length : 0 }); }; xhr.onerror = function () { console.log('[test] xhr error', { elapsedMs: Date.now() - xhrStartedAt, status: xhr.status }); }; xhr.ontimeout = function () { console.log('[test] xhr timeout', { elapsedMs: Date.now() - xhrStartedAt, readyState: xhr.readyState, status: xhr.status }); }; xhr.open( 'GET', 'https://example-addin-host.example.com/manifest.xml', true ); xhr.send(); setTimeout(function () { console.log('[test] completing event after wait'); event.completed({ allowEvent: true }); }, 6500); } root.OnAppointmentSendHandler = OnAppointmentSendHandler; Office.actions.associate( 'OnAppointmentSendHandler', OnAppointmentSendHandler ); })(this); Observed behavior The handler logs successfully. typeof fetch === "function". typeof XMLHttpRequest === "function". However: fetch(...) starts, but no response callback is logged. In earlier tests, fetch remained pending until our timeout marker. XMLHttpRequest reaches readyState: 1 after open(), but does not return useful response data. In some runs it eventually reports: status: 0, empty response, or timeout. Server-side logs show the request does not reach the server in the failing cases. event.completed(...) works and Outlook receives the completion. Things already ruled out / tested We are using absolute URLs, not relative URLs. We tested both: https://localhost:3000/... http://localhost:3000/... We tested through an HTTPS tunnel pointing to localhost. We tested trusted local HTTPS certificates; this does not appear to be a certificate trust issue. We configured .well-known/microsoft-officeaddins-allowed.json as documented for event-based CORS. We added the target domains to <AppDomains>. We tested public safe domains such as JSONPlaceholder-style endpoints. This does not appear to be ordinary CORS because in failing cases the request never reaches the server. The events.js bundle is intentionally simple and compatible with older JavaScript syntax. We avoided modern syntax and can provide an ES5/ES2015 version if needed. The runtime itself loads and executes the handler correctly.
new mail-account automatically forwards external mails to internal address
Hi, last week I created a new mail-account to our outlook-users and added a mail-license. Only internal mails was received in the new inbox and after troubleshooting and using mail-trace I discovered that the mails was forwarded to another internal inbox. This is not something that is configured anywhere in the mentioned settings when trying to troubleshoot forwarding-issues. How do I turn this off, so that my new employee can receive external e-mails. We don't have any policies or rules set up, that should trigger this behavior. Regards LarsOutllook does not receive read gmail.
I've been using Outlook 10 for years withouit this problem, but just opened a 365 account using Outlook classic. I've tried everything Google has to offer but can't fix the problem. Everything works fine but once I read a gmail on my phone or browser it will not be recieved by Outlook.
Outlook Android shows different date on shared recurring appointments
My wife and I share our hotmail calendars with each other For recurring appointments that she creates only, on any Android device using the Outlook app, the appointment is always 1 day later. It is consistent The time is correct so it doesn't seem to be a timezone issue. In Windows settings, Android settings, and outlook.com settings the time zone is Sydney AEST I've resynced the android apps. But tbh it has affected me for years, and has followed me across devices Any ideas? Pixel Outlook v5.2618.2 Samsung Outlook v5.2618.2 ty!
