At the Avast Knowledge Base (https://kb.support.business.avast.com/GetPublicArticle?title=BAV-Recommended-Components-Servers) you can read: "The following components should be uninstalled completely or disabled by setting the sliders to Off: Web Shield and Mail Shield"
Why this recomended configuration is not set by default?
Although the KBA is written open-ended for all servers, it's really for
Microsoft Exchange servers specifically because these components can conflict as explained in
No SMTP Server Defined Error in Avast Business AntivirusOn a Terminal Server enviroment, how Avast Business protect remote users/sessions without these shields on?
Because
Avast creates new processes for each terminal connection (session), running additional
Avast components besides the
File Shield can bring a terminal server to a crawl, especially if you have hundreds or thousands of terminals. We've also seen many instances of where additional
Avast's components can conflict with (and perhaps even detect) processes ran on a terminal server remotely from terminals. However, I encourage to thoroughly test within your environment (preferably a test/non-production environment) and use what settings work best. These are just settings we recommend to avoid possible conflicts and false positives without lengthy testing.