NotificationClient logs aren't purged and consume lots of disk in Exchange Server 2019 and 2016

Symptoms

In Microsoft Exchange Server 2019 or Exchange Server 2016, you find many logs accumulate in the following location, which consumes lots of disk:

C:\Program Files\Microsoft\Exchange Server\V15\Logging\NotificationBroker\Client

Resolution

To fix this issue, install one of the following updates:

For Exchange Server 2019, install the Cumulative Update 4 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.

For Exchange Server 2016, install the Cumulative Update 15 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.

References

Learn about the  terminology that Microsoft uses to describe software updates.