In a move that may bring relief to IT administrators, Microsoft has officially postponed the final Cumulative Update (CU) for Exchange Server 2019 into early 2025. Following a tumultuous November 2024 Security Update that disrupted email flows for some users, this delay offers a quieter end to the year for organizations relying on Exchange.

Originally scheduled for late 2024, the CU15 update will now arrive in January 2025, under the new label of H1 2025 CU. This shift aligns with Microsoft’s prior acknowledgment that December is an unfavorable time for updates due to potential disruptions during the holiday season. The delay mirrors patterns from 2022 and 2023, solidifying the expectation that end-of-year Exchange updates may no longer be the norm.

Administrators had already endured challenges stemming from the November 2024 Security Update, which broke critical transport rules and required a subsequent re-release to address bugs. This latest postponement gives IT teams a chance to stabilize systems and plan for what’s shaping up to be a hectic 2025.

With Exchange Server 2019 set to lose support on October 14, 2025, Microsoft is encouraging organizations to update to CU15 as soon as it becomes available. The update serves as a stepping stone for the in-place upgrade to Exchange Server SE, the highly anticipated successor expected in the second half of 2025.

Microsoft reiterated its advice: “Our guidance for all customers remains the same: get to Exchange Server 2019, install the latest update, and upgrade in-place to Exchange Server SE when available.”

While the delay may disrupt some IT roadmaps, it underscores Microsoft’s commitment to prioritizing update quality over strict deadlines. For now, administrators can look forward to a calmer holiday period, though the new year will undoubtedly bring a surge of activity.