{
  "$type": "site.standard.document",
  "bskyPostRef": {
    "cid": "bafyreie2jccgr3qy6rphu2o3eoal7xnvhs2annqnokqdcynmeka2ymvpcm",
    "uri": "at://did:plc:xxrzfynfiasdpbxteqxi4jgq/app.bsky.feed.post/3mhwfoeveunk2"
  },
  "description": "Outlook will improve handling of the x-ms-reactions: disallow header in Classic Outlook for Windows by disabling the Reactions button when reactions are disallowed and reverting failed attempts. This update, rolling out May-June 2026, ensures consistent behavior and reduces user confusion without...",
  "path": "/m365-message-center/message/mc1261593/",
  "publishedAt": "2026-03-26T01:00:06.000Z",
  "site": "https://blog.tophhie.cloud",
  "tags": [
    "558442",
    "Disallow reactions in Outlook | Microsoft Learn"
  ],
  "textContent": "**[Introduction]**\n\nWe’re improving how Outlook respects the**x‑ms‑reactions: disallow** header in Classic Outlook for Windows. This update ensures that when reactions are disallowed, the Reactions button is correctly disabled and any failed reaction attempts are fully reverted. This provides a more consistent and trustworthy user experience across Outlook clients and prevents user confusion.\n\nThis message is associated with Roadmap ID 558442.\n\n**[When this will happen:]**\n\n  * Public Preview (Worldwide): We will begin rolling out **early May 2026** and expect to complete by **late May 2026**.\n  * General Availability (Worldwide, GCC, GCC High, DoD): We will begin rolling out **early June 2026** and expect to complete by **late June 2026**.\n\n\n\n**[How this affects your organization:]**\n\n**Who is affected:**\n\n  * Users running Classic Outlook for Windows\n  * Organizations that disallow email reactions using the x‑ms‑reactions: disallow header\n\n\n\n**What will happen:**\n\n  * The Reactions button will appear grayed out when reactions are disallowed.\n  * Failed reaction attempts will be automatically undone in the UI.\n  * Users will no longer see misleading reaction states.\n  * Behavior will be consistent across all Outlook clients.\n  * The change is enabled by default and respects existing configurations.\n\n\n\n**[What you can do to prepare:]**\n\nNo action is required.\n\nYou may optionally:\n\n  * Inform helpdesk staff about the improved reaction behavior to reduce potential user questions.\n  * Review internal documentation if you reference reaction controls or messaging headers.\n  * Continue using the **x‑ms‑reactions: disallow** header as you do today; existing configurations are fully supported.\n\n\n\n**Learn more:** Disallow reactions in Outlook | Microsoft Learn\n\n**[Compliance considerations:]**\n\nNo compliance considerations identified, review as appropriate for your organization.",
  "title": "MC1261593: Outlook: Improved handling of disallowed and failed email reactions",
  "updatedAt": "2026-03-26T01:00:06.338Z"
}