MC1125491 (Updated) Microsoft Outlook for Windows: Add attachments while offline
Updated June 5, 2026: We have updated the timeline. Thank you for your patience. IntroductionWe’re enhancing offline functionality in the new Microsoft Outlook for Windows. This update (Microsoft 365 Roadmap ID 496371) enables users to add file attachments while composing emails offline, improving productivity for those working without an internet connection. When this will happen Targeted Release (Worldwide): Rollout begins in late October 2025 and is expected to complete by late March 2026 (previously late November 2025). General Availability (Worldwide): This is now currently available.General Availability (GCC): Rollout begins in early June 2026 (previously early May) and is expected to complete by end of June 2026 (previously late May).How this affects your organization Users with offline mode enabled in the new Outlook for Windows will be able to attach files to draft emails while