When you upload or attach files from a network location to a monitored location, e.g. email or web browser, Sophos data control does not scan them.
Known to apply to the following Sophos product(s) and version(s)
Sophos Endpoint Security and Control
Supported operating systems.
This failure to scan items in the way you would expect may well be because you have set your Sophos Anti-Virus on-access scanner to exclude ‘All remote files’. Data control uses the same set of exclusions as the Sophos Anti-Virus on-access scanner, so if remote file scanning is disabled it will not send any remote files for a data control check.
You may have configured your system in this way to aid in performance issues, and if so you need to be aware of the effects of this exclusion.
What To Do
Check your Sophos Anti-Virus on-access scanner settings and exclusions to ensure that they are best configured to meet your overall needs.