[Dovecot] Out of office reminder with sieve

[Johan Hendriks]

I found in the wiki the out of office reminder option.
But the sample is looking for a .out-of-office file.
I can not find out how to create this file.
I use roundcube to set the out of office with sieve.

what is the best way to implement this.

Second question, where are the addresses stored that have send an e-mail 
to the user who has out of office set?

thanks
regards,
Johan Hendriks