Legacy TLS tour continues with Exchange Online blocking old versions from July 2026
Microsoft readies the axe once again for yesterday's security
Office 365 is Microsoft's cloud productivity suite, whose identity, email, and data controls make its vulnerabilities and security advisories consequential.
Search across headline titles and summaries.
Background for this topic.
Office 365 is Microsoft’s cloud-hosted productivity and collaboration service, encompassing Exchange Online email, SharePoint, OneDrive, Teams, and web and desktop Office applications. Because these services store communications and business documents in a shared cloud environment, the tag includes both attacks against the platform and security issues arising from tenant configuration, identity, and connected applications.
Material risks include phishing or stolen credentials leading to account takeover, malicious OAuth applications gaining delegated access, mailbox forwarding rules, and excessive external sharing of files. Effective defenses include phishing-resistant multifactor authentication, conditional-access policies, least-privilege administration, controlled app consent, data-loss prevention, and review of audit and sign-in logs. Security teams must also track Microsoft advisories and client vulnerabilities, preserve cloud evidence for investigations, and apply retention, privacy, and compliance controls appropriate to the data stored in the tenant.
Microsoft readies the axe once again for yesterday's security
Microsoft readies the axe once again for yesterday's security Microsoft has warned users still clinging to legacy TLS versions that the end is nigh for TLS 1.0 and 1.1 on POP3 and IMAP4 connections to Exchange Online.…
Microsoft says it will start blocking legacy TLS connections for POP and IMAP email clients in Exchange Online starting in July 2026. [...]