The on-demand scanner is an important part of ESET Mail Security. It is used to perform scans of files and folders on your computer. To ensure the security of your network, it is essential that computer scans are not just run when an infection is suspected, but regularly as part of routine security measures. We recommend that you perform regular (for example, once a month) in-depth scans of your system to detect viruses not detected by Real-time file system protection. This can occur if a threat is introduced when Real-time file system protection is disabled, the virus signature database has not been updated, or if a file was not detected when it was first saved to the disk.


Two types of Computer scan are available. Smart scan quickly scans the system with no need for further configuration of the scan parameters. Custom scan allows you to select any of the predefined scan profiles and define specific scan targets.

See Scan progress for more information about the scanning process.

Mailbox Database scan - Lets you run On-demand mailbox database scan. You can choose Public folders, Mail Servers and Mailboxes to scan. Also, you can use Scheduler to run the database scan at a specific time or at an event.

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If you are running Microsoft Exchange Server 2007, 2010, 2013, 2016 or 2019 you can choose between Mailbox database protection and On-demand mailbox database scan, only one protection type can be active at a time. If you decide to use On-demand mailbox database scan you will need to disable integration of Mailbox database protection in Advanced setup under Server. Otherwise On-demand database scan will not be available.

Storage scan - Scans all shared folders on the local server. If Storage scan is not available, there are no shared folders on your server.

Hyper-V scan - This option is only visible in the menu if Hyper-V Manager is installed on the server that runs ESET Mail Security. Hyper-V scan allows for scanning of Virtual Machine (VM) disks on Microsoft Hyper-V Server without the need to have any "Agent" installed on the particular VM. See Hyper-V scan for more information (including supported host operating systems and limitations).

Smart scan - Allows you to quickly launch a computer scan and clean infected files with no need for user intervention. The advantage of Smart scan is that it is easy to operate and does not require detailed scanning configuration. Smart scan checks all files on local drives and automatically cleans or deletes detected infiltrations. The cleaning level is automatically set to the default value. For more detailed information on types of cleaning, see Cleaning.

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We recommend that you run a computer scan at least once a month. Scanning can be configured as a scheduled task from Tools > Scheduler.

Custom scan - Custom scan is an optimal solution if you want to specify scanning parameters such as scan targets and scanning methods. The advantage of Custom scan is the ability to configure scan parameters in detail. Configurations can be saved to user-defined scan profiles, which can be useful if scanning is repeatedly performed using the same parameters.

note_icon_example EXAMPLE

To select scan targets, select Computer scan > Custom scan and select an option from the Scan targets drop-down menu, or select specific targets from the tree structure. A scan target can also be specified by entering the path of the folder or file(s) you want to include. If you are only interested in scanning the system without additional cleaning actions, select Scan without cleaning. When performing a scan, you can choose from three cleaning levels by clicking Scan > Custom Scan > Setup... > ThreatSense parameters > Cleaning.

Performing computer scans with Custom scan is only recommended for advanced users with previous experience using antivirus programs.

Removable media scan - Similar to Smart scan - quickly launch a scan of removable media (such as CD/DVD/USB) that are connected to the computer. This may be useful when you connect a USB flash drive to a computer and want to scan its content for malware and other potential threats. This type of scan can be also initiated by clicking Custom scan and then selecting Removable media from the Scan targets drop-down menu and clicking Scan.

Repeat last scan - Repeats your last scan operation using the exact same settings.

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Repeat last scan function is not available if On-demand mailbox database scan is present.