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Microsoft to Block Legacy TLS Connections for Exchange Online in July 2026

Microsoft to Block Legacy TLS Connections for Exchange Online in July 2026

First seen 29 Apr 2026, 19:05 UTC

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ThreatCluster AI
ThreatCluster April 30, 2026 at 19:05 UTC
  • Microsoft will block TLS 1.0 and 1.1 for Exchange Online POP and IMAP connections starting July 2026.
  • Users must ensure their email clients support TLS 1.2 or later to avoid connection issues.
  • The change is part of a broader industry trend to enhance security by retiring outdated encryption protocols.

Microsoft has announced plans to deprecate support for legacy TLS versions (TLS 1.0 and TLS 1.1) for POP and IMAP connections to Exchange Online, starting in July 2026. This change will require all connections to use TLS 1.2 or later, impacting users of older email clients and devices that do not support these newer protocols. Microsoft expects minimal disruption as most users already utilize modern TLS versions. However, users who have opted into legacy endpoints may face connection failures. The move aligns with broader industry efforts to enhance internet security by retiring outdated encryption protocols. Organizations are advised to ensure their email clients are updated to avoid potential issues. This deprecation follows years of warnings from Microsoft about the risks associated with legacy TLS versions.

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Updated 133d ago How this analysis works

Timeline

2020-01-01
Support for TLS 1.0 and 1.1 in Exchange Online officially ended.
2023-01-01
Microsoft announced plans to disable legacy TLS versions for POP3 and IMAP4.
2026-04-28
Microsoft confirmed deprecation of legacy TLS versions for Exchange Online.
2026-07-01
Blocking of legacy TLS connections for Exchange Online begins.

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