Information
Exchange must have anti-spam filtering installed.
GROUP ID: V-259626
RULE ID: SV-259626r961161
Originators of spam messages are constantly changing their techniques to defeat spam countermeasures; therefore, spam software must be constantly updated to address the changing threat. Spam protection mechanisms include, for example, signature definitions, rule sets, and algorithms.
Exchange 2019 provides both anti-spam and anti-malware protection out of the box. The Exchange 2019 anti-spam and anti-malware product capabilities are limited but still provide some protection.
Solution
Install the anti-Spam module.
Open the Exchange Management Shell and enter the following command:
& $env:ExchangeInstallPath\Scripts\Install-anti-SpamAgents.ps1