Change scl value action not working

Question / Problem

I am using the rule action "Change SCL value" but the Exchange Server Toolbox does not set the value. Why does it not work?

Answer / Solution

The SCL value of an email can only be set if you are using an Exchange Server and even then only if there is no other email server between the Exchange Server and the Exchange Server Toolbox setting the value.

If an Exchange Server recieves an email with Exchange Server specific header content it will automatically ignore and overwrite these values.