(Updated) Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

(Updated) Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

Message ID: MC1287370 (Updated) Updated April 22, 2026: We have updated the timeline and content. Thank you for your patience. [Introduction]Microsoft is introducing an automatic upgrade for shared calendars in Outlook and Exchange Online, transitioning from the legacy MAPI-based model to…
(Updated) Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

(Updated) Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

Message ID: MC1287370 (Updated) Updated April 21, 2026: We have updated the timeline. Thank you for your patience. [Introduction]Microsoft is introducing an automatic upgrade for shared calendars in Outlook and Exchange Online, transitioning from the legacy MAPI-based model to the modern…
Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

Auto upgrade of shared calendars from legacy MAPI model to modern REST model [MC1287370]

Message ID: MC1287370 [Introduction]Microsoft is introducing an automatic upgrade for shared calendars in Outlook and Exchange Online, transitioning from the legacy MAPI-based model to the modern REST-based model. This server-side upgrade will improve calendar sync reliability, performance, and consistency for…
Exchange Online, SharePoint Online, and Microsoft Teams: April 2026 industry-wide DigiCert Global Root CA (G1) distrust [MC1282565]

Exchange Online, SharePoint Online, and Microsoft Teams: April 2026 industry-wide DigiCert Global Root CA (G1) distrust [MC1282565]

Message ID: MC1282565 [Introduction]To support industry-wide security improvements and modern cryptographic standards, browsers and platforms that follow Mozilla and Chrome trust stores will begin distrusting the DigiCert Global Root CA (G1) starting April 15, 2026. Microsoft has already migrated Microsoft 365 services…
(Updated) Microsoft 365 admin center: Organizational Messages to support email delivery [MC1189665]

(Updated) Microsoft 365 admin center: Organizational Messages to support email delivery [MC1189665]

Message ID: MC1189665 (Updated) Updated April 16, 2026: We have updated the timeline. Thank you for your patience. [Introduction]Organizational Messages will soon include email as a delivery channel, expanding beyond existing surfaces such as the Windows Taskbar, Windows Notifications, Windows Spotlight,…
Message center post structure updates may require admin script changes [MC1282308]

Message center post structure updates may require admin script changes [MC1282308]

Message ID: MC1282308 (Updated) [Introduction:] We’re updating the Microsoft 365 Message center post structure to provide more consistent, concise, and actionable communications. This change standardizes section headings across Message center posts to improve readability, support automation scenarios, and enable future…