Microsoft to block legacy TLS connections for POP and IMAP in Exchange Online

As detailed in Bleeping Computer, 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 means that POP3 and IMAP4 connections will require TLS 1.2 or later. Any connections attempting to use TLS 1.0 or TLS 1.1 will fail, potentially causing legacy applications or devices, as well as custom or embedded systems, to stop connecting. Microsoft advises customers using POP or IMAP to access email via Exchange Online to ensure their clients and applications support TLS 1.2 or later and to update any custom or embedded applications that may rely on older TLS versions.

This move aligns with a broader industry trend, including actions by major browsers and guidance from the NSA, to retire outdated and insecure encryption protocols and enhance overall internet traffic security against eavesdropping and tampering.

Source: Bleeping Computer