On the Mailbox configuration screen (E-mail tab -> List of Domains -> Specific Domain -> Mailboxes -> Edit Mailbox for a particular mailbox) check the Vacation box. This will turn on the automatic responder for a particular e-mail account.
It is possible to plan ahead when to turn off the automatic responder. You can choose whether to specify a concrete date or define the number of days after which the responder will switch off. When defining the number of days, the responder will turn off on the last day of the number of days you define. So if on Monday you enter 1, the responder will turn off on Tuesday. If you enter 5, it will turn off on Saturday.
In the next box you can enter the e-mail address to which the automatic reply will not be sent. If you need to enter multiple addresses, enter the first address, click on the Save button and go again to the box Mailbox Edit. A new box will appear where you may enter another address. In the second section, enter the subject and text of the email that will be sent as an automatic response. Confirm the settings by clicking the Save button.