The Lua function 'VPOP3.SetSetting' sets a general setting forVPOP3
It takes two parameters:
The function returns one value:
A third optional boolean parameter is possible. If this is set to 'true', then the setting will be created even if it doesn't exist. If it is absent or set to 'false', then the setting will not be created if it does not already exist (and the function will return false)