[Dovecot] Sieve, vacation, company (domain-wide) message possible?

[Charles Marcus]

Hello,

I've been using vacation.pl from postfixadmin for many years, and since 
the most recent modification that allows me to specify my own strings to 
test for for when NOT to send a message, I'm extremely happy with it (no 
more auto-responses to linked-in/facebook crap, etc)...

But, there is one thing I'd like to be able to do that it can't do, and 
there hasn't been any positive response about implementing it, so I'm 
asking about if this is possible to do with sieve right now, and if not, 
how hard would it be to implement...

What I'd like is to be able to set a company (domain-wide) auto-response 
for when our company is closed for holidays... more specifically, extra 
holidays (often the boss will close an extra day for an extra long 
weekend). He has asked more than once about setting an auto-response for 
*everyone* during these periods...

Thanks,

-- 

Best regards,

*/Charles/*