Microsoft's October Windows Server Updates Are Breaking Exchange Sign-In and Mail Flow
Microsoft’s October Patch Tuesday came with a nasty surprise for email admins. Over the weekend, the company confirmed that this month’s Windows Server security updates are breaking Outlook Web Access sign-in and mail delivery on some on-premises Exchange Server systems, and its advice is blunt: don’t uninstall the patch, tweak the registry instead. The admission went up on Microsoft’s Windows release health dashboard, as reported by BleepingComputer and several security outlets on Sunday and Monday. Users on affected servers may find they can’t sign in to Outlook on the web at all, or that messages sent from Outlook sit in the Outbox forever, never delivered. In some cases Exchange also struggles to reach mailboxes during mailbox replication, and mail queues grow. ...