Can I set up a Content Filter that is Time/Date stamp dependent?

Question

My company would like to add an additional disclaimer text during Holidays where the company is closed.  It will say something like: "In observance of the 'XYZ' holiday, our offices will be closing at 3:00 PM on Friday, December........ and will reopen at 8:30 AM Monday.......".
I was wondering if there is a way to set up conditions in an Outgoing content filter to only include that text if the email is sent between certain dates.
This would allow me to set up the filters prior to the holidays and not have to manage them manually.
I tried to do it via Exchange Transport rule, but I can't find a time/date dependent condition for the rules in Exchange.
Thanks,
Rachel    

Answer 1

Hi Rachel,
there is no way to archive this directly in content filters, an indirect way would be to use a message filter that adds an additional header (i.e. X-mas: true) during a specific period. For that, message filters provide the 'date' rule, i.e
HolidayHeader:
if ((date > '12/20/2012 13:00:00') and
     (date < '12/28/2012 12:00:00'))
insert-header('X-mas', 'TRUE');
You'd then create an outbound content filter matching on this header and inserting the specific footer if the header exists. Or, of course, you could have that action in the message filter already, however in that case you need additional conditions to make sure the rule applies on outbound messages only.
Hope that helps,
Andreas