No Sentinel Anti-malware is not designed to be an email scanner. Sentinel Anti-malware is designed to scan and monitor your clients web files. The threat landscape in shared hosted environments is unique from that of the standard AV products detection suite in that they are detecting primarily OS level trojans, rootkits and traditional file-infecting viruses but missing the ever increasing variety of malware on the user account level which serves as an attack platform.
If you require email scanning then take a look at our Warden Anti-spam and Virus Protection product:
https://www.danami.com/products/plesk-extensions/warden-antispam-and-virus-protection
