WebClient's weak performance when using Microsoft Defender or Sophos AV

We have recently observed an issue with WebClient performing slow when Microsoft Defender or Sophos AV is used on the Windows Server (might be related to Microsoft Updates released on 01/22).

To fix this performance issue, please adjust the following scanning options in Microsoft Defender:

• add an exception for the IceWarp installation folder
• add an exception for the following Icewarp's data directories: temp, mail, archive, logs (paths can be found in Admin console under System > Storage > Directories)
• add an exception for the following services: smtp.exe, pop3.exe, im.exe, control.exe, cal.exe, mysqld.exe
• add an exception for MySQL/MariaDB installation folder
• add an exception for MySQL/MariaDB data storage (data folder where databases are stored physically on the filesystem)