Vacation reply
The vacation notice answers incoming messages automatically for as long as it is active.
Who gets no reply
Section titled “Who gets no reply”Newsletters and mailing lists are excluded. That is intended: an automatic reply to a mailing list goes to every subscriber and gets embarrassing fast.
The date range does not work yet
Section titled “The date range does not work yet”The form offers a date range (from/to) field. It says itself that automatic activation by date is planned but currently not saved.
In practice that means: the vacation reply applies from the moment you switch it on until you switch it off again. Prepare it for a holiday and trust the start date, and it will reply from right now. So switch it on the day you leave, and off by hand when you are back.