Last time looked there was a temp greeting capability, though not sure if the same as on Magix. Its similar to the one from the INDeX.
once logged into the mailbox,
'3' to administer greetings
'3' to activate a greeting
'1' The number of the greeting to activate (assuming '1' is recorded'
System will then prompt for what purpose the greeting is to be activated.
1-for all calls
2-for Internal Calls
3-for External Calls
4-for Number Enaged/Busy
5-for Timeout/no answer
8-for Default
9-for Temp
'9' To activate for Temp Greeting
System will then prompt for a number of days for the greeting to be activated followed by '#'.
Once the number of days have elapsed, the greeting setup previously configured is restored.
As well as via the Phone Manager, theres probably other ways to set the temp greeting.