Symptoms
After you install the Microsoft Exchange Server 2019 or 2016 November 2024 security update (SU) Version 1, Exchange Server stops processing Exchange Transport Rules (ETR) and Data Loss Prevention (DLP) rules. In some cases, rules might be processed for a few hours before the process stops working. After you restart the MSExchangeTransport service, rules begin to process but stop again. Although the symptoms occur, you see no evidence of the issue, such as event log entries.Â
ResolutionÂ
To fix this issue, install the following security update: