Clean up old OWA files automatically to free up disk space

Symptoms 

Every cumulative update (CU) or security update (SU) installs additional files in the Outlook on the web (OWA) subfolders of the default installation location for Exchange Server. The subfolders are named by using the corresponding CU or SU build number. Over time, the additional files can consume lots of disk space on the installation volume. Starting in Exchange Server 2019 CU15, Exchange Server Setup removes the additional files that are no longer needed. This frees up space on the installation volume.

Resolution 

To fix this issue, install the following cumulative update: 

• Cumulative Update 15 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019