Symptoms
A Delivery Flow Control setting override is now available so that you can increase the throttling limits in the store driver to avoid throttling issues in emergency transport situations.
Resolution
To fix this issue, install Cumulative Update 13 or a later cumulative update for Exchange Server 2019.
More information
The fix for this issue was first released in the February 14, 2023, security update for Exchange Server. For more information about the override, see Microsoft Exchange Transport service stops and returns Event ID 17018.