Microsoft is investigating an Exchange Online issue that incorrectly quarantines mailboxes, blocks emails, and causes calendar problems.

Microsoft has pulled the November 2024 Exchange security updates released during this month's Patch Tuesday because of email delivery issues on servers using custom mail flow rules. This issue affects ...

Microsoft has re-released the November 2024 security updates for Exchange Server after pulling them earlier this month due to email delivery issues on servers using custom mail flow rules. This known ...

Microsoft's July 2026 Exchange Server security updates are now available, including patches for a critical vulnerability affecting supported versions.