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)