SetUserMailVacation()
From Rackspace Email & Apps API
This function will set the string to be the user's vacation message and will set whether or not the vacation message should be active.
Input Parameters
Five strings, one integer:
Administrative username, Administrative password, Domain name, User name, Vacation message, Vacation message on (int, 0=on, 1=off)
Return Values
If successful, the return value of the function will be 1.
Consult the Result Code Table for a list of result codes and their meaning.