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Microsoft 365 & Identity knowledge center

Clear guidance for Microsoft 365, Entra identity, account protection, collaboration, endpoint policy, and lifecycle changes.

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Microsoft 365 & Identity

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DSE visual briefIdentity & cloud

Exchange Online’s Reject Direct Send setting blocks anonymous mail from your own domains: add partner connectors first

Exchange Online’s RejectDirectSend setting, off by default, rejects anonymous messages whose envelope sender uses one of the tenant’s accepted domains unless a mail flow connector attributes them. Devices and services that send as your domain need a partner connector first, and Microsoft plans to enable it by default for new tenants.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

Skype for Business Server 2015 and 2019 have been out of support since October 2025: plan Teams or Subscription Edition

Microsoft’s lifecycle pages list Skype for Business Server 2015 and 2019 extended support ending 10/15/2025 (6:59:59 AM Pacific). Skype for Business Server Subscription Edition, under the Modern Lifecycle Policy since July 1, 2025, can only be installed as an in-place upgrade from Skype for Business Server 2019.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

SharePoint Server 2016 and 2019 left extended support in July 2026: move to Subscription Edition or SharePoint Online

Microsoft’s lifecycle pages list SharePoint Server 2016 and 2019 extended support ending 7/15/2026 (6:59:59 AM Pacific), and its 2026 end-of-support list adds Project Server 2016 and 2019, SharePoint Designer 2013 and InfoPath 2013 on July 14, 2026. SharePoint Server Subscription Edition follows the Modern Lifecycle Policy and is in support.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

Microsoft Publisher reached end of life in October 2026: find and convert .pub files to PDF or Word

Microsoft says Publisher reaches end of life in October 2026: Microsoft 365 subscribers lose access on or shortly after October 1, 2026 and can no longer open or edit Publisher files in Publisher, and perpetual-version support ends October 13, 2026. Microsoft recommends converting .pub files to PDF or Word.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

Exchange Online is disabling EWS from October 2026 to April 2027: inventory apps and set an AppID allow list

Microsoft’s EWS deprecation page says Exchange Web Services starts to be disabled globally in Exchange Online in October 2026 and is fully disabled in April 2027. Under enforcement, setting EWSEnabled to True without an EWSAllowedAppIDs list blocks all EWS traffic, and tenants left unset will have EWS disabled.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

Office 2016 and 2019 lost support in October 2025, and Office 2021 and Office LTSC 2021 followed in October 2026

Microsoft’s lifecycle pages list Office 2016 and Office 2019 extended support ending 10/15/2025, and Office 2021 and Office LTSC 2021 ending 10/14/2026 (6:59:59 AM Pacific). Microsoft’s 2025 list shows the 2016 and 2019 apps, including Outlook, Publisher and Skype for Business, ending support on October 14, 2025.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefManaged IT operations

Exchange Server 2016 and 2019 have been out of support since October 14, 2025: move to Exchange SE or online

Microsoft’s lifecycle pages show Exchange Server 2016 and 2019 reached end of support on October 14, 2025, after which there are no new security updates or assisted support. Exchange Server Subscription Edition, which started July 1, 2025 under the Modern Lifecycle Policy, is listed as in support.

Published Reviewed 2 min readBy DSE Security Editorial Team
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DSE visual briefIdentity & cloud

Use carrier account locks and change alerts against SIM swaps, and check when the FCC’s new rules take effect

The FCC’s November 2023 SIM swap and port-out fraud order requires wireless carriers to authenticate customers before moving a number, notify them of SIM changes and port requests, and offer account locks. A 2024 bureau order tied compliance to a later Federal Register notice.

Published Reviewed 2 min readBy DSE Security Editorial Team
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