The new Outlook for Windows, also known as the One Outlook client, does not support public folders by default. This is a deliberate design choice by Microsoft, as the new client relies on REST APIs and the Microsoft 365 cloud infrastructure, which lack the legacy MAPI protocol support required for public folders. This article explains … Read more
You set custom overlay colors for shared calendars in Outlook, but the colors revert to default after closing and reopening the application. This happens because Outlook stores overlay color preferences in a local file that can become corrupted or conflict with cached data. This article explains why the colors reset and provides step-by-step fixes to … Read more
You receive a meeting invitation in Outlook, but the automatic RSVP response — Accept, Tentative, or Decline — does not appear in the sender’s tracking view. This problem typically occurs when Outlook processes the meeting request but fails to send the response due to a corrupted profile, a restrictive add-in, or an incorrect setting in … Read more
You have Microsoft 365 Copilot licensed and enabled, but the Copilot Summary button does not appear in the new Outlook for Windows. This usually happens because the Copilot license is not assigned to your user account, the Outlook version is outdated, or the feature is disabled in the Microsoft 365 admin center. This article explains … Read more
After installing a recent Microsoft 365 update, some users report that the Copilot button in the classic version of Outlook has disappeared from the ribbon. This problem occurs because the update may have disabled the Copilot add-in, reset ribbon customizations, or triggered a feature policy that hides the button. This article explains the three most … Read more
You search for an email in Outlook and the results appear correctly, but when you click a message the preview pane shows nothing — no subject, no body, just a white or gray area. This issue typically occurs because the reading pane is in a corrupted state, an add-in interferes with the rendering engine, or … Read more
You open a draft on your laptop, make a few edits, and then find the same draft appears as a second copy on your phone. This duplication happens because Outlook syncs drafts through the server, but each device can create a new version of the draft instead of updating the original. The root cause is … Read more
When you receive a meeting request in Outlook, the email body sometimes shows raw code instead of a formatted calendar invitation. This happens because Outlook cannot interpret the MIME content type of the message. The result is a plain text email with garbled characters or HTML tags instead of the Accept, Tentative, and Decline buttons. … Read more
When you send an update to an existing Outlook meeting, some attendees report they never received the change. This problem occurs when the meeting update is not processed correctly by the organizer’s Exchange server or when the attendee’s Outlook client rejects the update due to conflicting calendar entries. This article explains the root causes of … Read more
After migrating your mailbox to a new server or a different Microsoft 365 tenant, your Outlook rules may stop running. The rules remain visible in the Rules and Alerts dialog but do not fire for incoming or outgoing messages. This happens because the rule conditions or actions reference the old server path, folder IDs, or … Read more