Description of the Problem
In the recent release of the Antivirus client version 19.7, several users have encountered issues with the Mail Shield being disabled on Windows 7 operating systems. This issue affects both Avast and AVG Business products.
While Avast is currently working on solving the issue, we do not currently have a resolution or workaround for the problem. We understand the inconvenience and security concerns this causes for our customers and are working with all due haste towards resolution.
Resolution
Avast has released a fix for this issue in Microupdate 552, which was put into production January 17th, 2020. This microupdate will require a reboot of the affected computer(s.)
Reference https://kb.support.business.avast.com/GetPublicArticle?title=Mail-Shield-Disabled-Win7